Clinical Focus

  • Biochemical Genetics
  • Metabolism, Inborn Errors
  • Clinical Biochemical Genetics

Academic Appointments

  • Clinical Associate Professor, Pathology

Professional Education

  • Medical Education: University of South Florida Morsani College of Medicine (2002) FL
  • Residency: University of South Florida Pediatric Residency (2005) FL
  • Residency: Stanford University Division of Medical Genetics (2007) CA
  • Fellowship: Stanford University Clinical Biochemical Genetics Fellowship (2008) CA
  • Fellowship: National Institute Of Health Medical Genetics and Genomics Fellowship (2015) MD
  • Board Certification: American Board of Pediatrics, Pediatrics (2005)
  • Board Certification: American Board of Medical Genetics and Genomics, Clinical Biochemical Genetics (2009)
  • Board Certification: American Board of Medical Genetics and Genomics, Clinical Molecular Genetics and Genomics (2015)
  • Board Certification: American Board of Medical Genetics and Genomics, Clinical Genetics and Genomics (2018)

2023-24 Courses

All Publications

  • A homozygous Gly470Ala variant in PEX6 causes severe Zellweger spectrum disorder. American journal of medical genetics. Part A Galarreta, C. I., Wong, K., Carmichael, J., Woods, J., Tise, C. G., Niehaus, A. D., Schildt, A. J., Verscaj, C. P., Cusmano-Ozog, K. P. 2023


    Zellweger spectrum disorder (ZSD) is a group of autosomal recessive disorders caused by biallelic pathogenic variants in any one of the 13 PEX genes essential for peroxisomal biogenesis. We report a cohort of nine infants who presented at birth with severe neonatal features suggestive of ZSD and found to be homozygous for a variant in PEX6 (NM_000287.4:c.1409G > C[p.Gly470Ala]). All were of Mixtec ancestry and identified by the California Newborn Screening (NBS) Program to have elevated C26:0-lysophosphatidylcholine but no reportable variants in ABCD1. The clinical and biochemical features of this cohort are described within. Gly470Ala may represent a founder variant in the Mixtec population of Central California. ZSD should be considered in patients who present at birth with severe hypotonia and enlarged fontanelles, especially in the setting of an abnormal NBS, Mixtec ancestry, or family history of infant death. There is a need to further characterize the natural history of ZSD, the Gly470Ala variant, and expand upon possible genotype-phenotype correlations.

    View details for DOI 10.1002/ajmg.a.63234

    View details for PubMedID 37144748

  • MT-ATP6 mitochondrial disease identified by newborn screening reveals a distinct biochemical phenotype. American journal of medical genetics. Part A Tise, C. G., Verscaj, C. P., Mendelsohn, B. A., Woods, J., Lee, C. U., Enns, G. M., Stander, Z., Hall, P. L., Cowan, T. M., Cusmano-Ozog, K. P. 2023


    Although decreased citrulline is used as a newborn screening (NBS) marker to identify proximal urea cycle disorders (UCDs), it is also a feature of some mitochondrial diseases, including MT-ATP6 mitochondrial disease. Here we describe biochemical and clinical features of 11 children born to eight mothers from seven separate families who were identified with low citrulline by NBS (range 3-5muM; screening cutoff >5) and ultimately diagnosed with MT-ATP6 mitochondrial disease. Follow-up testing revealed a pattern of hypocitrullinemia together with elevated propionyl-(C3) and 3-hydroxyisovaleryl-(C5-OH) acylcarnitines, and a homoplasmic pathogenic variant in MT-ATP6 in all cases. Single and multivariate analysis of NBS data from the 11 cases using Collaborative Laboratory Integrated Reports (CLIR; demonstrated citrulline <1st percentile, C3>50th percentile, and C5-OH >90th percentile when compared with reference data, as well as unequivocal separation from proximal UCD cases and false-positive low citrulline cases using dual scatter plots. Five of the eight mothers were symptomatic at the time of their child(ren)'s diagnosis, and all mothers and maternal grandmothers evaluated molecularly and biochemically had a homoplasmic pathogenic variant in MT-ATP6, low citrulline, elevated C3, and/or elevated C5-OH. All molecularly confirmed individuals (n=17) with either no symptoms (n=12), migraines (n=1), or a neurogenic muscle weakness, ataxia, and retinitis pigmentosa (NARP) phenotype (n=3) were found to have an A or U mitochondrial haplogroup, while one child with infantile-lethal Leigh syndrome had a B haplogroup.

    View details for DOI 10.1002/ajmg.a.63159

    View details for PubMedID 36883293

  • Neonatal lupus is a novel cause of positive newborn screening for X-linked adrenoleukodystrophy. American journal of medical genetics. Part A Niehaus, A. D., Mendelsohn, B. A., Zimmerman, B., Lee, C. U., Manning, M. A., Cusmano-Ozog, K. P., Tise, C. G. 2023


    We report three unrelated individuals, each exposed to maternal autoantibodies during gestation and found to have elevated very long-chain fatty acids (VLCFAs) in the newborn period after screening positive by California newborn screening (NBS) for X-linked adrenoleukodystrophy (ALD). Two probands presented with clinical and laboratory features of neonatal lupus erythematosus (NLE); the third had features suggestive of NLE and a known maternal history of Sjogren's syndrome and rheumatoid arthritis. In all three individuals, subsequent biochemical and molecular evaluation for primary and secondary peroxisomal disorders was nondiagnostic with normalization of VLCFAs by 15months of age. These cases add to the expanding differential diagnosis to consider in newborns who screen positive for ALD via elevated C26:0-lysophosphatidylcholine. Though the pathophysiology of how transplacental maternal anti-Ro antibodies damage fetal tissue is not well-understood, we postulate that the VLCFA elevations reflect a systemic inflammatory response and secondary peroxisomal dysfunction that improves once maternal autoantibodies wane after birth. Additional evaluation of this phenomenon is warranted to better understand the intricate biochemical, clinical, and possible therapeutic overlap between autoimmunity, inflammation, peroxisomal dysfunction, and human disease.

    View details for DOI 10.1002/ajmg.a.63144

    View details for PubMedID 36863699

  • Creatine Transporter Deficiency Presenting as Failure to Thrive: A Case Report of a Novel SLC6A8 Variant Causing a Treatable but Likely Underdiagnosed Genetic Disorder. Journal of investigative medicine high impact case reports Tise, C. G., Palma, M. J., Cusmano-Ozog, K. P., Matalon, D. R. 2023; 11: 23247096231154438


    Cerebral creatine deficiency syndromes (CCDS) are a rare group of inherited metabolic disorders (IMDs) that often present with nonspecific findings including global developmental delay (GDD), intellectual disability (ID), seizures, hypotonia, and behavioral differences. Creatine transporter (CRTR) deficiency is the most common CCDS, exhibiting X-linked inheritance and an estimated prevalence as high as 2.6% in individuals with neurodevelopmental disorders. Here, we present a 20-month-old boy with worsening failure to thrive (FTT) and GDD admitted for evaluation. He was found to have persistently low serum creatinine levels and a family history notable for a mother with learning disabilities and a maternal male cousin with GDD. Urine analyses revealed a marked elevation of creatine and elevated creatine:creatinine ratio suggestive of CRTR deficiency. Molecular genetic testing of SLC6A8 identified a maternally inherited hemizygous variant and brain magnetic resonance spectroscopy (MRS) showed diffusely diminished creatine peaks, further supporting the diagnosis of CRTR deficiency. The proband was started on creatine, arginine, and glycine supplementation and has demonstrated improved development. This case highlights that CRTR deficiency should be considered in all patients presenting with FTT and abnormal neurodevelopmental features, particularly if creatinine levels are low on serum chemistry studies. The nonspecific presentation of this condition in males and females likely has resulted in CRTR deficiency being underdiagnosed. There are existing therapies for individuals affected with CRTR deficiency and other CCDS, highlighting the importance of early diagnosis and intervention for affected individuals.

    View details for DOI 10.1177/23247096231154438

    View details for PubMedID 36752093

  • Optimization of the biochemical genetics laboratory rotation using a multidesign approach to curriculum. Genetics in medicine : official journal of the American College of Medical Genetics Bosfield, K., Albert, J., Cheng, N., Swaringer, T., Cusmano-Ozog, K., Regier, D. S. 2022


    A biochemical genetics laboratory rotation is required for multiple genetics training programs. Traditionally, this rotation has been observational with experience being dependent upon cases released and availability of laboratory director(s), resulting in inconsistent learning opportunities. This curriculum was created to standardize the learning experience.The revised rotation provides multiple teaching modalities including small group didactic sessions (flipped classroom model), case-based sessions, and hands-on laboratory experience. Trainees prepare a presentation (learning by teaching) and discuss the differential diagnosis, metabolic pathway, newborn screening, treatment, and molecular characteristics of the gene(s) implicated. Learner assessment is performed using pre- and post-tests, learner evaluations, and instructor feedback.Pre- and post-test scores were significantly different (P < .001) for learners from all programs. Participants found the course to be effective, increased their learning, and allowed them to interact with metabolic testing results in helpful ways. Faculty appreciated the use of prerecorded lectures and additional time for in-depth teaching on interesting cases.The revised rotation has been well received by trainees and faculty. Interaction of learners with the laboratory staff was optimized by ensuring all parties were prepared to teach and learn. Future directions include expanding the program to include remote learners from other centers.

    View details for DOI 10.1016/j.gim.2022.11.008

    View details for PubMedID 36484781

  • Recent tPA administration can cause pseudo-hyperargininemia and may mimic arginase deficiency or arginine supplementation. JIMD reports Cusmano-Ozog, K. P., Renck, A. K., Tise, C. G. 2022; 63 (6): 563-567


    Individuals suspected of or diagnosed with a rare disorder, including inherited metabolic disorders (IMD), often need frequent and/or urgent vascular access for blood draws and treatment, making central indwelling catheters commonly used devices in this patient population. These indwelling catheters are prone to thrombosis, limiting vascular access. This complication is frequently resolved with the use of altepase, a recombinant tissue plasminogen activator (tPA). This report describes two individuals, one with a known IMD and one undergoing evaluation for an IMD, who were found to have hyperargininemia (>500 muM; reference 10-140 muM) by plasma amino acid (PAA) analysis of a specimen collected ~1.5-3 h after clearance of an indwelling catheter with tPA. In both cases, hyperargininemia resolved with repeat testing, suggesting pseudo-hyperargininemia secondary to tPA administration. Quantitative amino acid analysis of the administered tPA demonstrated an arginine level of ~200mM, supporting tPA as the cause of pseudo-hyperargininemia. Certain formulations of tPA contain high concentrations of arginine, which if not cleared properly can result in marked elevations of arginine, mimicking arginase deficiency or suggesting arginine supplementation. Thus, the possibility of pseudohyperargininemia due to tPA administration should be considered when obtaining PAAs from an indwelling catheter in any individual being evaluated or managed for an IMD.

    View details for DOI 10.1002/jmd2.12328

    View details for PubMedID 36341162

  • Genomic and biochemical analysis of repeatedly observed variants in DBT in individuals with maple syrup urine disease of Central American ancestry. American journal of medical genetics. Part A Billington, C. J., Chapman, K. A., Leon, E., Meltzer, B. W., Berger, S. I., Olson, M., Figler, R. A., Hoang, S. A., Wanxing, C., Wamhoff, B. R., Collado, M. S., Cusmano-Ozog, K. 2022; 188 (9): 2738-2749


    Maple syrup urine disease (MSUD) is an intoxication-type inherited metabolic disorder in which hyperleucinemia leads to brain swelling and death without treatment. MSUD is caused by branched-chain alpha-ketoacid dehydrogenase deficiency due to biallelic loss of the protein products from the genes BCKDHA, BCKDHB, or DBT, while a distinct but related condition is caused by loss of DLD. In this case series, eleven individuals with MSUD caused by two pathogenic variants in DBT are presented. All eleven individuals have a deletion of exon 2 (delEx2, NM_001918.3:c.48_171del); six individuals are homozygous and five individuals are compound heterozygous with a novel missense variant (NM_001918.5:c.916 T > C [p.Ser306Pro]) confirmed to be in trans. Western Blot indicates decreased amount of protein product in delEx2;c.916 T > C liver cells and absence of protein product in delEx2 homozygous hepatocytes. Ultrahigh performance liquid chromatography-tandem mass spectrometry demonstrates an accumulation of branched-chain amino acids and alpha-ketoacids in explanted hepatocytes. Individuals with these variants have a neonatal-onset, non-thiamine-responsive, classical form of MSUD. Strikingly, the entire cohort is derived from families who immigrated to the Washington, DC, metro area from Honduras or El Salvador suggesting the possibility of a founder effect.

    View details for DOI 10.1002/ajmg.a.62893

    View details for PubMedID 35799415

    View details for PubMedCentralID PMC9542135

  • Measurement of lysosomal enzyme activities: A technical standard of the American College of Medical Genetics and Genomics (ACMG). Genetics in medicine : official journal of the American College of Medical Genetics Strovel, E. T., Cusmano-Ozog, K., Wood, T., Yu, C. 2022; 24 (4): 769-783


    Assays that measure lysosomal enzyme activity are important tools for the screening and diagnosis of lysosomal storage disorders (LSDs). They are often ordered in combination with urine oligosaccharide and glycosaminoglycan analysis, additional biomarker assays, and/or DNA sequencing when an LSD is suspected. Enzyme testing in whole blood/leukocytes, serum/plasma, cultured fibroblasts, or dried blood spots demonstrating deficient enzyme activity remains a key component of LSD diagnosis and is often prompted by characteristic clinical findings, abnormal newborn screening, abnormal biochemical findings (eg, elevated glycosaminoglycans), or molecular results indicating pathogenic variants or variants of uncertain significance in a gene associated with an LSD. This document, which focuses on clinical enzyme testing for LSDs, provides a resource for laboratories to develop and implement clinical testing, to describe variables that can influence test performance and interpretation of results, and to delineate situations for which follow-up molecular testing is warranted.

    View details for DOI 10.1016/j.gim.2021.12.013

    View details for PubMedID 35394426

  • Laboratory analysis of acylcarnitines, 2020 update: a technical standard of the American College of Medical Genetics and Genomics (ACMG). Genetics in medicine : official journal of the American College of Medical Genetics Miller, M. J., Cusmano-Ozog, K., Oglesbee, D., Young, S. 2021; 23 (2): 249-258


    Acylcarnitine analysis is a useful test for identifying patients with inborn errors of mitochondrial fatty acid β-oxidation and certain organic acidemias. Plasma is routinely used in the diagnostic workup of symptomatic patients. Urine analysis of targeted acylcarnitine species may be helpful in the diagnosis of glutaric acidemia type I and other disorders in which polar acylcarnitine species accumulate. For newborn screening applications, dried blood spot acylcarnitine analysis can be performed as a multiplex assay with other analytes, including amino acids, succinylacetone, guanidinoacetate, creatine, and lysophosphatidylcholines. Tandem mass spectrometric methodology, established more than 30 years ago, remains a valid approach for acylcarnitine analysis. The method involves flow-injection analysis of esterified or underivatized acylcarnitines species and detection using a precursor-ion scan. Alternative methods utilize liquid chromatographic separation of isomeric and isobaric species and/or detection by selected reaction monitoring. These technical standards were developed as a resource for diagnostic laboratory practices in acylcarnitine analysis, interpretation, and reporting.

    View details for DOI 10.1038/s41436-020-00990-1

    View details for PubMedID 33071282

  • Aicardi-Goutières syndrome may present with positive newborn screen for X-linked adrenoleukodystrophy. American journal of medical genetics. Part A Tise, C. G., Morales, J. A., Lee, A. S., Velez-Bartolomei, F. n., Floyd, B. J., Levy, R. J., Cusmano-Ozog, K. P., Feigenbaum, A. S., Ruzhnikov, M. R., Lee, C. U., Enns, G. M. 2021


    We report three unrelated probands, two male and one female, diagnosed with Aicardi-Goutières syndrome (AGS) after screening positive on California newborn screening (CA NBS) for X-linked adrenoleukodystrophy (X-ALD) due to elevated C26:0 lysophosphatidylcholine (C26:0-LPC). Follow-up evaluation was notable for elevated C26:0, C26:1, and C26:0/C22:0 ratio, and normal red blood cell plasmalogens levels in all three probands. Diagnoses were confirmed by molecular sequencing prior to 12 months of age after clinical evaluation was inconsistent with X-ALD or suggestive of AGS. For at least one proband, the early diagnosis of AGS enabled candidacy for enrollment into a therapeutic clinical trial. This report demonstrates the importance of including AGS on the differential diagnosis for individuals who screen positive for X-ALD, particularly infants with abnormal neurological features, as this age of onset would be highly unusual for X-ALD. While AGS is not included on the Recommended Universal Screening Panel, affected individuals can be identified early through state NBS programs so long as providers are aware of a broader differential that includes AGS. This report is timely, as state NBS algorithms for X-ALD are actively being established, implemented, and refined.

    View details for DOI 10.1002/ajmg.a.62160

    View details for PubMedID 33683010

  • Biallelic variants in KYNU cause a multisystemic syndrome with hand hyperphalangism. Bone Ehmke, N., Cusmano-Ozog, K., Koenig, R., Holtgrewe, M., Nur, B., Mihci, E., Babcock, H., Gonzaga-Jauregui, C., Overton, J. D., Xiao, J., Martinez, A. F., Muenke, M., Balzer, A., Jochim, J., El Choubassi, N., Fischer-Zirnsak, B., Huber, C., Kornak, U., Elsea, S. H., Cormier-Daire, V., Ferreira, C. R. 2020; 133: 115219


    Catel-Manzke syndrome is characterized by the combination of Pierre Robin sequence and radial deviation, shortening as well as clinodactyly of the index fingers, due to an accessory ossification center. Mutations in TGDS have been identified as one cause of Catel-Manzke syndrome, but cannot be found as causative in every patient with the clinical diagnosis. We performed a chromosome microarray and/or exome sequencing in three patients with hand hyperphalangism, heart defect, short stature, and mild to severe developmental delay, all of whom were initially given a clinical diagnosis of Catel-Manzke syndrome. In one patient, we detected a large deletion of exons 1-8 and the missense variant c.1282C > T (p.Arg428Trp) in KYNU (NM_003937.2), whereas homozygous missense variants in KYNU were found in the other two patients (c.989G > A (p.Arg330Gln) and c.326G > C (p.Trp109Ser)). Plasma and urine metabolomic analysis of two patients indicated a block along the tryptophan catabolic pathway and urine organic acid analysis showed excretion of xanthurenic acid. Biallelic loss-of-function mutations in KYNU were recently described as a cause of NAD deficiency with vertebral, cardiac, renal and limb defects; however, no hand hyperphalangism was described in those patients, and Catel-Manzke syndrome was not discussed as a differential diagnosis. In conclusion, we present unrelated patients identified with biallelic variants in KYNU leading to kynureninase deficiency and xanthurenic aciduria as a very likely cause of their hyperphalangism, heart defect, short stature, and developmental delay. We suggest performance of urine organic acid analysis in patients with suspected Catel-Manzke syndrome, particularly in those with cardiac or vertebral defects or without mutations in TGDS.

    View details for DOI 10.1016/j.bone.2019.115219

    View details for PubMedID 31923704

  • Laboratory diagnosis of disorders of peroxisomal biogenesis and function: a technical standard of the American College of Medical Genetics and Genomics (ACMG). Genetics in medicine : official journal of the American College of Medical Genetics De Biase, I., Tortorelli, S., Kratz, L., J Steinberg, S., Cusmano-Ozog, K., Braverman, N. 2020; 22 (4): 686-697


    Peroxisomal disorders are a clinically and genetically heterogeneous group of diseases caused by defects in peroxisomal biogenesis or function, usually impairing several metabolic pathways. Peroxisomal disorders are rare; however, the incidence may be underestimated due to the broad spectrum of clinical presentations. The inclusion of X-linked adrenoleukodystrophy to the Recommended Uniform Screening Panel for newborn screening programs in the United States may increase detection of this and other peroxisomal disorders. The current diagnostic approach relies heavily on biochemical genetic tests measuring peroxisomal metabolites, including very long-chain and branched-chain fatty acids in plasma and plasmalogens in red blood cells. Molecular testing can confirm biochemical findings and identify the specific genetic defect, usually utilizing a multiple-gene panel or exome/genome approach. When next-generation sequencing is used as a first-tier test, evaluation of peroxisome metabolism is often necessary to assess the significance of unknown variants and establish the extent of peroxisome dysfunction. This document provides a resource for laboratories developing and implementing clinical biochemical genetic testing for peroxisomal disorders, emphasizing technical considerations for sample collection, test performance, and result interpretation. Additionally, considerations on confirmatory molecular testing are discussed.

    View details for DOI 10.1038/s41436-019-0713-9

    View details for PubMedID 31822849

  • Growth, development, and phenotypic spectrum of individuals with deletions of 2q33.1 involving SATB2. Clinical genetics Zarate, Y. A., Bosanko, K. A., Thomas, M. A., Miller, D. T., Cusmano-Ozog, K. n., Martinez-Monseny, A. n., Curry, C. J., Graham, J. M., Velsher, L. n., Bekheirnia, M. R., Seidel, V. n., Dedousis, D. n., Mitchell, A. L., DiMarino, A. M., Riess, A. n., Balasubramanian, M. n., Fish, J. L., Caffrey, A. R., Fleischer, N. n., Pierson, T. M., Lacro, R. V. 2020


    SATB2-Associated syndrome (SAS) is an autosomal dominant, multisystemic, neurodevelopmental disorder due to alterations in SATB2 at 2q33.1. A limited number of individuals with 2q33.1 contiguous deletions encompassing SATB2 (ΔSAS) have been described in the literature. We describe 17 additional individuals with ΔSAS, review the phenotype of 33 previously published individuals with 2q33.1 deletions (n=50, mean age=8.5±7.8 years), and provide a comprehensive comparison to individuals with other molecular mechanisms that result in SAS (non-ΔSAS). Individuals in the ΔSAS group were often underweight for age (20/41=49%) with a progressive decline in weight (95% CI=-2.3 to -1.1, p<0.0001) and height (95% CI=-2.3 to -1.0, p<0.0001) Z-score means from birth to last available measurement. ΔSAS individuals were often noted to a broad spectrum of facial dysmorphism. A composite image of ΔSAS individuals generated by automated image analysis was distinct as compared to matched controls and non-ΔSAS individuals. We also present additional genotype-phenotype correlations for individuals in the ΔSAS group such as an increased risk for aortic root/ascending aorta dilation and primary pulmonary hypertension for those individuals with contiguous gene deletions that include COL3A1/COL5A2 and BMPR2, respectively. Based on these findings, we provide additional care recommendations for individuals with ΔSAS variants. This article is protected by copyright. All rights reserved.

    View details for DOI 10.1111/cge.13912

    View details for PubMedID 33381861

  • Clinical and molecular spectrum of CHOPS syndrome. American journal of medical genetics. Part A Raible, S. E., Mehta, D., Bettale, C., Fiordaliso, S., Kaur, M., Medne, L., Rio, M., Haan, E., White, S. M., Cusmano-Ozog, K., Nishi, E., Guo, Y., Wu, H., Shi, X., Zhao, Q., Zhang, X., Lei, Q., Lu, A., He, X., Okamoto, N., Miyake, N., Piccione, J., Allen, J., Matsumoto, N., Pipan, M., Krantz, I. D., Izumi, K. 2019; 179 (7): 1126-1138


    CHOPS syndrome is a multisystem disorder caused by missense mutations in AFF4. Previously, we reported three individuals whose primary phenotype included cognitive impairment and coarse facies, heart defects, obesity, pulmonary involvement, and short stature. This syndrome overlaps phenotypically with Cornelia de Lange syndrome, but presents distinct differences including facial features, pulmonary involvement, and obesity. Here, we provide clinical descriptions of an additional eight individuals with CHOPS syndrome, as well as neurocognitive analysis of three individuals. All 11 individuals presented with features reminiscent of Cornelia de Lange syndrome such as synophrys, upturned nasal tip, arched eyebrows, and long eyelashes. All 11 individuals had short stature and obesity. Congenital heart disease and pulmonary involvement were common, and those were seen in about 70% of individuals with CHOPS syndrome. Skeletal abnormalities are also common, and those include abnormal shape of vertebral bodies, hypoplastic long bones, and low bone mineral density. Our observation indicates that obesity, pulmonary involvement, skeletal findings are the most notable features distinguishing CHOPS syndrome from Cornelia de Lange syndrome. In fact, two out of eight of our newly identified patients were found to have AFF4 mutations by targeted AFF4 mutational analysis rather than exome sequencing. These phenotypic findings establish CHOPS syndrome as a distinct, clinically recognizable disorder. Additionally, we report three novel missense mutations causative for CHOPS syndrome that lie within the highly conserved, 14 amino acid sequence of the ALF homology domain of the AFF4 gene, emphasizing the critical functional role of this region in human development.

    View details for DOI 10.1002/ajmg.a.61174

    View details for PubMedID 31058441

  • FGF21 underlies a hormetic response to metabolic stress in methylmalonic acidemia. JCI insight Manoli, I., Sysol, J. R., Epping, M. W., Li, L., Wang, C., Sloan, J. L., Pass, A., Gagne, J., Ktena, Y. P., Li, L., Trivedi, N. S., Ouattara, B., Zerfas, P. M., Hoffmann, V., Abu-Asab, M., Tsokos, M. G., Kleiner, D. E., Garone, C., Cusmano-Ozog, K., Enns, G. M., Vernon, H. J., Andersson, H. C., Grunewald, S., Elkahloun, A. G., Girard, C. L., Schnermann, J., DiMauro, S., Andres-Mateos, E., Vandenberghe, L. H., Chandler, R. J., Venditti, C. P. 2018; 3 (23)


    Methylmalonic acidemia (MMA), an organic acidemia characterized by metabolic instability and multiorgan complications, is most frequently caused by mutations in methylmalonyl-CoA mutase (MUT). To define the metabolic adaptations in MMA in acute and chronic settings, we studied a mouse model generated by transgenic expression of Mut in the muscle. Mut-/-;TgINS-MCK-Mut mice accurately replicate the hepatorenal mitochondriopathy and growth failure seen in severely affected patients and were used to characterize the response to fasting. The hepatic transcriptome in MMA mice was characterized by the chronic activation of stress-related pathways and an aberrant fasting response when compared with controls. A key metabolic regulator, Fgf21, emerged as a significantly dysregulated transcript in mice and was subsequently studied in a large patient cohort. The concentration of plasma FGF21 in MMA patients correlated with disease subtype, growth indices, and markers of mitochondrial dysfunction but was not affected by renal disease. Restoration of liver Mut activity, by transgenesis and liver-directed gene therapy in mice or liver transplantation in patients, drastically reduced plasma FGF21 and was associated with improved outcomes. Our studies identify mitocellular hormesis as a hepatic adaptation to metabolic stress in MMA and define FGF21 as a highly predictive disease biomarker.

    View details for PubMedID 30518688

  • Tissue acylcarnitine status in a mouse model of mitochondrial β-oxidation deficiency during metabolic decompensation due to influenza virus infection. Molecular genetics and metabolism Tarasenko, T. N., Cusmano-Ozog, K., McGuire, P. J. 2018; 125 (1-2): 144-152


    Despite judicious monitoring and care, patients with fatty acid oxidation disorders may experience metabolic decompensation due to infection which may result in rhabdomyolysis, cardiomyopathy, hypoglycemia and liver dysfunction and failure. Since clinical studies on metabolic decompensation are dangerous, we employed a preclinical model of metabolic decompensation due to infection. By infecting mice with mouse adapted influenza and using a pair-feeding strategy in a mouse model of long-chain fatty acid oxidation (Acadvl-/-), our goals were to isolate the effects of infection on tissue acylcarnitines and determine how they relate to their plasma counterparts. Applying statistical data reduction techniques (Partial Least Squares-Discriminant Analysis), we were able to identify critical acylcarnitines that were driving differentiation of our experimental groups for all the tissues studied. While plasma displayed increases in metabolites directly related to mouse VLCAD deficiency (e.g. C16 and C18), organs like the heart, muscle and liver also showed involvement of alternative pathways (e.g. medium-chain FAO and ketogenesis), suggesting adaptive measures. Matched correlation analyses showed strong correlations (r > 0.7) between plasma and tissue levels for a small number of metabolites. Overall, our results demonstrate that infection as a stress produces perturbations in metabolism in Acadvl-/- that differ greatly from WT infected and Acadvl-/- pair-fed controls. This model system will be useful for studying the effects of infection on tissue metabolism as well as evaluating interventions aimed at modulating the effects of metabolic decompensation.

    View details for DOI 10.1016/j.ymgme.2018.06.012

    View details for PubMedID 30031688

    View details for PubMedCentralID PMC6626496

  • Extending the phenotypic spectrum of Sengers syndrome: Congenital lactic acidosis with synthetic liver dysfunction. Translational science of rare diseases Beck, D. B., Cusmano-Ozog, K., Andescavage, N., Leon, E. 2018; 3 (1): 45-48


    Sengers syndrome is a rare autosomal recessive mitochondrial disease characterized by lactic acidosis, hypertrophic cardiomyopathy and bilateral cataracts. We present here a case of neonatal demise, within the first day of life, who initially presented with severe lactic acidosis, with evidence of both chorioamnionitis and cardiogenic shock. Initial metabolic labs demonstrated a severe lactic acidosis prompting genetic testing which revealed a homozygous pathogenic variant for Sengers syndrome in AGK, c.979A >  T; p.K327*. In addition to the canonical features of Sengers syndrome, our patient is the first reported case with liver dysfunction extending the phenotypic spectrum both in terms of severity and complications. This case also highlights the importance of maintaining a broad differential for congenital lactic acidosis.

    View details for DOI 10.3233/TRD-180020

    View details for PubMedID 29682452

    View details for PubMedCentralID PMC5904566

  • Prenatal treatment of ornithine transcarbamylase deficiency. Molecular genetics and metabolism Wilnai, Y. n., Blumenfeld, Y. J., Cusmano, K. n., Hintz, S. R., Alcorn, D. n., Benitz, W. E., Berquist, W. E., Bernstein, J. A., Castillo, R. O., Concepcion, W. n., Cowan, T. M., Cox, K. L., Lyell, D. J., Esquivel, C. O., Homeyer, M. n., Hudgins, L. n., Hurwitz, M. n., Palma, J. P., Schelley, S. n., Akula, V. P., Summar, M. L., Enns, G. M. 2018


    Patients with neonatal urea cycle defects (UCDs) typically experience severe hyperammonemia during the first days of life, which results in serious neurological injury or death. Long-term prognosis despite optimal pharmacological and dietary therapy is still poor. The combination of intravenous sodium phenylacetate and sodium benzoate (Ammonul®) can eliminate nitrogen waste independent of the urea cycle. We report attempts to improve outcomes for males with severe ornithine transcarbamylase deficiency (OTCD), a severe X-linked condition, via prenatal intravenous administration of Ammonul and arginine to heterozygous carrier females of OTCD during labor.Two heterozygote OTCD mothers carrying male fetuses with a prenatal diagnosis of OTCD received intravenous Ammonul, arginine and dextrose-containing fluids shortly before birth. Maintenance Ammonul and arginine infusions and high-caloric enteral nutrition were started immediately after birth. Ammonul metabolites were measured in umbilical cord blood and the blood of the newborn immediately after delivery. Serial ammonia and biochemical analyses were performed following delivery.Therapeutic concentrations of Ammonul metabolites were detected in umbilical cord and neonatal blood samples. Plasma ammonia and glutamine levels in the postnatal period were within the normal range. Peak ammonia levels in the first 24-48h were 53mcmol/l and 62mcmol/l respectively. The boys did not experience neurological sequelae secondary to hyperammonemia and received liver transplantation at ages 3months and 5months. The patients show normal development at ages 7 and 3years.Prenatal treatment of mothers who harbor severe OTCD mutations and carry affected male fetuses with intravenous Ammonul and arginine, followed by immediate institution of maintenance infusions after delivery, results in therapeutic levels of benzoate and phenylacetate in the newborn at delivery and, in conjunction with high-caloric enteral nutrition, prevents acute hyperammonemia and neurological decompensation. Following initial medical management, early liver transplantation may improve developmental outcome.

    View details for PubMedID 29396029

  • Confirmation that MAT1A p.Ala259Val mutation causes autosomal dominant hypermethioninemia. Molecular genetics and metabolism reports Muriello, M. J., Viall, S., Bottiglieri, T., Cusmano-Ozog, K., Ferreira, C. R. 2017; 13: 9-12


    Methionine adenosyltransferase (MAT) I/III deficiency is an inborn error of metabolism caused by mutations in MAT1A, encoding the catalytic subunit of MAT responsible for the synthesis of S-adenosylmethionine, and is characterized by persistent hypermethioninemia. While historically considered a recessive disorder, a milder autosomal dominant form of MAT I/III deficiency occurs, though only the most common mutation p.Arg264His has ample evidence to prove dominant inheritance. We report a case of hypermethioninemia caused by the p.Ala259Val substitution and provide evidence of autosomal dominant inheritance by showing both maternal inheritance of the mutation and concomitant hypermethioninemia. The p.Ala259Val mutation falls in the dimer interface, and thus likely leads to dominant inheritance by a similar mechanism to that described in the previously reported dominant negative mutation, that is, by means of interference with subunits encoded by the wild-type allele.

    View details for DOI 10.1016/j.ymgmr.2017.07.004

    View details for PubMedID 28748147

    View details for PubMedCentralID PMC5512230

  • Plasma fibroblast growth factor-21 levels in patients with inborn errors of metabolism. Molecular genetics and metabolism reports Kirmse, B., Cabrerra-Luque, J., Ayyub, O., Cusmano, K., Chapman, K., Summar, M. 2017; 13: 52-54


    Fibroblast growth factor-21 (FGF21) levels are elevated in patients with primary mitochondrial disorders but have not been studied in patients with inborn errors of metabolism (IEM) known to have secondary mitochondrial dysfunction. We measured plasma FGF21 by ELISA in patients with and without IEM. FGF21 levels were higher in patients with IEM compared to without IEM (370 pg/dL vs. 0-65 pg/dL). Further study of FGF21 as a biomarker in IEM is warranted.

    View details for DOI 10.1016/j.ymgmr.2017.04.001

    View details for PubMedID 28920014

    View details for PubMedCentralID PMC5586549

  • Correction of hyperleucinemia in MSUD patients on leucine-free dietary therapy. Molecular genetics and metabolism Scott, A. I., Cusmano-Ozog, K., Enns, G. M., Cowan, T. M. 2017


    PURPOSE: Maple Syrup Urine Disease (MSUD) is a rare disorder of branched-chain amino acid catabolism associated with encephalopathy from accumulation of leucine. Leucine is closely monitored during normal growth and particularly during acute illness. As most hospitals do not have access to rapid plasma amino acid quantification, the initial management is often empirical. A model describing the reduction of plasma leucine in hyperleucinemic patients on leucine-free formula would help to guide management and optimize testing frequency.METHODS: We retrospectively reviewed charts from 15 MSUD patients comprising 29 episodes of hyperleucinemia that were managed with leucine-free formula. Episodes were categorized by clinical presentation.RESULTS: Upon leucine restriction, plasma leucine concentrations fell exponentially at a rate proportional to approximately 50% of the starting value over each 24-hour period. Recovery appears to be sensitive to clinical status and triggering event of the hyperleucinemic episode. Patients with upper respiratory infections generally recovered slowly, while cases of dietary non-adherence resolved more quickly.CONCLUSION: This general model may help anticipate leucine levels during clinical management of MSUD patients when using nutritional support and leucine-free formula. The response of individual patients may vary depending on clinical status and triggering factors.

    View details for PubMedID 29032949

  • Time-dependent negative bias in plasma ammonia samples in a clinical setting. Clinica chimica acta; international journal of clinical chemistry Ayyub, O. B., Hofherr, S., Cusmano-Ozog, K., Ah Mew, N. 2017; 471: 126-127

    View details for DOI 10.1016/j.cca.2017.05.011

    View details for PubMedID 28595139

  • Spurious Elevation of Multiple Urine Amino Acids by Ion-Exchange Chromatography in Patients with Prolidase Deficiency. JIMD reports Ferreira, C. R., Cusmano-Ozog, K. 2017; 31: 45-49


    The enzyme prolidase cleaves dipeptides where the C-terminal amino acid corresponds to proline or hydroxyproline. As a consequence, a deficiency of this enzyme leads to accumulation of these dipeptides, which correspondingly are found to be elevated in urine. In fact, the absence of dipeptiduria is sufficient to rule out a diagnosis of prolidase deficiency. However, given the fact that these dipeptides elute at the same position as more common amino acids, the analyzer's software will instead call an elevation of these corresponding amino acids. Thus, an elevation of glycylproline, aspartylproline, glutamylproline, threonylproline and serylproline, valylproline, leucylproline, isoleucylproline, alanylproline, phenylalanylproline, and lysylproline will instead be interpreted as an elevation of leucine, citrulline, methionine, isoleucine, beta-aminoisobutyric acid, gamma-aminobutyric acid, ethanolamine, tyrosine, histidine, and anserine/carnosine, respectively. This particular profile of elevated amino acids, however, can easily be overlooked. We hope that the recognition of this characteristic pattern of falsely elevated urinary amino acids will aid in the recognition of prolidase deficiency.

    View details for DOI 10.1007/8904_2016_552

    View details for PubMedID 27067078

    View details for PubMedCentralID PMC5388643

  • Diagnosis of LCHAD/TFP deficiency in an at risk newborn using umbilical cord blood acylcarnitine analysis. Molecular genetics and metabolism reports Raval, D. B., Cusmano-Ozog, K. P., Ayyub, O., Jenevein, C., Kofman, L. H., Lanpher, B., Hauser, N., Regier, D. S. 2017; 10: 8-10


    Trifunctional protein deficiency/Long-chain hydroxyacyl-CoA dehydrogenase deficiency (LCHAD/TFP) deficiency is a disorder of fatty acid oxidation and ketogenesis. Severe neonatal lactic acidosis, cardiomyopathy, and hepatic dysfunction are caused by the accumulation of toxic long-chain acylcarnitines. The feasibility of umbilical cord blood use in screening for acylcarnitine analysis and free carnitine has been hypothesized but not reported in LCHAD/TFP neonates. We present a 4 week old female who was at risk of inheriting LCHAD/TFP deficiency and was diagnosed at the time of delivery using umbilical cord blood. Umbilical cord blood was collected at delivery and sent for acylcarnitine analysis. Treatment was started immediately. Acylcarnitine analysis demonstrated findings that are consistent with a biochemical diagnosis of LCHAD/TFP deficiency. Patients with LCHAD/TFP deficiency should have treatment initiated as early as possible to avoid acute decompensation and minimize the long-term complications of the disorder including cardiomyopathy. In pregnancies at risk of having a child with LCHAD/TFP deficiency, umbilical cord blood sample is an efficient method to diagnose an inborn error of metabolism such as LCHAD/TFP deficiency.

    View details for DOI 10.1016/j.ymgmr.2016.11.007

    View details for PubMedID 27995076

    View details for PubMedCentralID PMC5155040

  • Hereditary fructose intolerance mimicking a biochemical phenotype of mucolipidosis: A review of the literature of secondary causes of lysosomal enzyme activity elevation in serum. American journal of medical genetics. Part A Ferreira, C. R., Devaney, J. M., Hofherr, S. E., Pollard, L. M., Cusmano-Ozog, K. 2017; 173 (2): 501-509


    We describe a patient with failure to thrive, hepatomegaly, liver dysfunction, and elevation of multiple plasma lysosomal enzyme activities mimicking mucolipidosis II or III, in whom a diagnosis of hereditary fructose intolerance (HFI) was ultimately obtained. She presented before introduction of solid foods, given her consumption of a fructose-containing infant formula. We present the most extensive panel of lysosomal enzyme activities reported to date in a patient with HFI, and propose that multiple enzyme elevations in plasma, especially when in conjunction with a normal plasma α-mannosidase activity, should elicit a differential diagnosis of HFI. We also performed a review of the literature on the different etiologies of elevated lysosomal enzyme activities in serum or plasma. © 2016 Wiley Periodicals, Inc.

    View details for DOI 10.1002/ajmg.a.38023

    View details for PubMedID 27797444

  • The proteome of methylmalonic acidemia (MMA): the elucidation of altered pathways in patient livers. Molecular bioSystems Caterino, M., Chandler, R. J., Sloan, J. L., Dorko, K., Cusmano-Ozog, K., Ingenito, L., Strom, S. C., Imperlini, E., Scolamiero, E., Venditti, C. P., Ruoppolo, M. 2016; 12 (2): 566-74


    Methylmalonic acidemia (MMA) is a heterogeneous and severe autosomal recessive inborn error of metabolism most commonly caused by the deficient activity of the vitamin B12 dependent enzyme, methylmalonyl-CoA mutase (MUT). The main treatment for MMA patients is the dietary restriction of propiogenic amino acids and carnitine supplementation. Despite treatment, the prognosis for vitamin B12 non-responsive patients remains poor and is associated with neonatal lethality, persistent morbidity and decreased life expectancy. While multi-organ pathology is a feature of MMA, the liver is severely impacted by mitochondrial dysfunction which likely underlies the metabolic instability experienced by the patients. Liver and/or combined liver/kidney transplantation is therefore sometimes performed in severely affected patients. Using liver specimens from donors and MMA patients undergoing elective liver transplantation collected under a dedicated natural history protocol ( NCT00078078), we employed proteomics to characterize the liver pathology and impaired hepatic metabolism observed in the patients. Pathway analysis revealed perturbations of enzymes involved in energy metabolism, gluconeogenesis and Krebs cycle anaplerosis. Our findings identify new pathophysiologic and therapeutic targets that could be valuable for designing alternative therapies to alleviate clinical manifestations seen in this disorder.

    View details for DOI 10.1039/c5mb00736d

    View details for PubMedID 26672496

    View details for PubMedCentralID PMC4858437

  • Kupffer cells modulate hepatic fatty acid oxidation during infection with PR8 influenza. Biochimica et biophysica acta Tarasenko, T. N., Singh, L. N., Chatterji-Len, M., Zerfas, P. M., Cusmano-Ozog, K., McGuire, P. J. 2015; 1852 (11): 2391-401


    In response to infection, patients with inborn errors of metabolism may develop a functional deterioration termed metabolic decompensation. The biochemical hallmarks of this disruption of metabolic homeostasis are disease specific and may include acidosis, hyperammonemia or hypoglycemia. In a model system previously published by our group, we noted that during influenza infection, mice displayed a depression in hepatic mitochondrial enzymes involved in nitrogen metabolism. Based on these findings, we hypothesized that this normal adaptation may extend to other metabolic pathways, and as such, may impact various inborn errors of metabolism. Since the liver is a critical organ in inborn errors of metabolism, we carried out untargeted metabolomic profiling of livers using mass spectrometry in C57Bl/6 mice infected with influenza to characterize metabolic adaptation. Pathway analysis of metabolomic data revealed reductions in CoA synthesis, and long chain fatty acyl CoA and carnitine species. These metabolic adaptations coincided with a depression in hepatic long chain β-oxidation mRNA and protein. To our surprise, the metabolic changes observed occurred in conjunction with a hepatic innate immune response, as demonstrated by transcriptional profiling and flow cytometry. By employing an immunomodulation strategy to deplete Kupffer cells, we were able to improve the expression of multiple genes involved in β-oxidation. Based on these findings, we are the first to suggest that the role of the liver as an immunologic organ is central in the pathophysiology of hepatic metabolic decompensation in inborn errors of metabolism due to respiratory viral infection.

    View details for DOI 10.1016/j.bbadis.2015.08.021

    View details for PubMedID 26319418

    View details for PubMedCentralID PMC6662236

  • What is in the can? The dilemma with dietary supplements. Molecular genetics and metabolism D'Aco, K., Mooney, R., Cusmano-Ozog, K., Hofherr, S., Lichter-Konecki, U. 2014; 113 (4): 239-40

    View details for DOI 10.1016/j.ymgme.2014.10.009

    View details for PubMedID 25453401

  • Degree of Glutathione Deficiency and Redox Imbalance Depend on Subtype of Mitochondrial Disease and Clinical Status PLOS ONE Enns, G. M., Moore, T., Le, A., Atkuri, K., Shah, M. K., Cusmano-Ozog, K., Niemi, A., Cowan, T. M. 2014; 9 (6)


    Mitochondrial disorders are associated with decreased energy production and redox imbalance. Glutathione plays a central role in redox signaling and protecting cells from oxidative damage. In order to understand the consequences of mitochondrial dysfunction on in vivo redox status, and to determine how this varies by mitochondrial disease subtype and clinical severity, we used a sensitive tandem mass spectrometry assay to precisely quantify whole blood reduced (GSH) and oxidized (GSSG) glutathione levels in a large cohort of mitochondrial disorder patients. Glutathione redox potential was calculated using the Nernst equation. Compared to healthy controls (n = 59), mitochondrial disease patients (n = 58) as a group showed significant redox imbalance (redox potential -251 mV ± 9.7, p<0.0001) with an increased level of oxidation by ∼ 9 mV compared to controls (-260 mV ± 6.4). Underlying this abnormality were significantly lower whole blood GSH levels (p = 0.0008) and GSH/GSSG ratio (p = 0.0002), and significantly higher GSSG levels (p<0.0001) in mitochondrial disease patients compared to controls. Redox potential was significantly more oxidized in all mitochondrial disease subgroups including Leigh syndrome (n = 15), electron transport chain abnormalities (n = 10), mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (n = 8), mtDNA deletion syndrome (n = 7), mtDNA depletion syndrome (n = 7), and miscellaneous other mitochondrial disorders (n = 11). Patients hospitalized in metabolic crisis (n = 7) showed the greatest degree of redox imbalance at -242 mV ± 7. Peripheral whole blood GSH and GSSG levels are promising biomarkers of mitochondrial dysfunction, and may give insights into the contribution of oxidative stress to the pathophysiology of the various mitochondrial disorders. In particular, evaluation of redox potential may be useful in monitoring of clinical status or response to redox-modulating therapies in clinical trials.

    View details for DOI 10.1371/journal.pone.0100001

    View details for Web of Science ID 000338508200063

    View details for PubMedCentralID PMC4062483

  • Concurrent non-ketotic hyperglycinemia and propionic acidemia in an eight year old boy. Molecular genetics and metabolism reports Kruszka, P. S., Kirmse, B., Zand, D. J., Cusmano-Ozog, K., Spector, E., Van Hove, J. L., Chapman, K. A. 2014; 1: 237-240


    This is the first reported case of a patient with both non-ketotic hyperglycinemia and propionic acidemia. At 2 years of age, the patient was diagnosed with non-ketotic hyperglycinemia by elevated glycine levels and mutations in the GLDC gene (paternal allele: c.1576_1577insC delT and c.1580delGinsCAA; p.S527Tfs*13, and maternal allele: c.1819G>A; p.G607S). At 8 years of age after having been placed on ketogenic diet, he became lethargic and had severe metabolic acidosis with ketonuria. Urine organic acid analysis and plasma acylcarnitine profile were consistent with propionic acidemia. He was found to have an apparently homozygous mutation in the PCCB gene: c.49C>A; p.Leu17Met. The patient was also treated with natural protein restriction, carnitine, biotin, and thiamine and had subjective and biochemical improvement.

    View details for DOI 10.1016/j.ymgmr.2014.04.007

    View details for PubMedID 27896094

    View details for PubMedCentralID PMC5121296

  • Thiamine pyrophosphokinase deficiency causes a Leigh Disease like phenotype in a sibling pair: identification through whole exome sequencing and management strategies. Molecular genetics and metabolism reports Fraser, J. L., Vanderver, A., Yang, S., Chang, T., Cramp, L., Vezina, G., Lichter-Konecki, U., Cusmano-Ozog, K. P., Smpokou, P., Chapman, K. A., Zand, D. J. 2014; 1: 66-70


    We present a sibling pair with Leigh-like disease, progressive hypotonia, regression, and chronic encephalopathy. Whole exome sequencing in the younger sibling demonstrated a homozygous thiamine pyrophosphokinase (TPK) mutation. Initiation of high dose thiamine, niacin, biotin, α-lipoic acid and ketogenic diet in this child demonstrated improvement in neurologic function and re-attainment of previously lost milestones. The diagnosis of TPK deficiency was difficult due to inconsistent biochemical and diagnostic parameters, rapidity of clinical demise and would not have been made in a timely manner without the use of whole exome sequencing. Molecular diagnosis allowed for attempt at dietary modification with cofactor supplementation which resulted in an improved clinical course.

    View details for DOI 10.1016/j.ymgmr.2013.12.007

    View details for PubMedID 27896076

    View details for PubMedCentralID PMC5121315

  • Expansion of the TARP syndrome phenotype associated with de novo mutations and mosaicism. American journal of medical genetics. Part A Johnston, J. J., Sapp, J. C., Curry, C., Horton, M., Leon, E., Cusmano-Ozog, K., Dobyns, W. B., Hudgins, L., Zackai, E., Biesecker, L. G. 2014; 164A (1): 120-128


    The TARP syndrome (Talipes equinovarus, Atrial septal defect, Robin sequence, and Persistent left superior vena cava) is an X-linked disorder that was determined to be caused by mutations in RBM10 in two families, and confirmed in a subsequent case report. The first two original families were quite similar in phenotype, with uniform early lethality although a confirmatory case report showed survival into childhood. Here we report on five affecteds from three newly recognized families, including patients with atypical manifestations. None of the five patients had talipes and others also lacked cardinal TARP features of Robin sequence and atrial septal defect. All three families demonstrated de novo mutations, and one of the families had two recurrences, with demonstrable maternal mosaicism. © 2013 Wiley Periodicals, Inc.

    View details for DOI 10.1002/ajmg.a.36212

    View details for PubMedID 24259342

  • A rapid, sensitive method for quantitative analysis of underivatized amino acids by liquid chromatography-tandem mass spectrometry (LC-MS/MS) JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES Le, A., Ng, A., Kwan, T., Cusmano-Ozog, K., Cowan, T. M. 2014; 944: 166-174


    The quantitation of free amino acids from physiologic samples is essential for diagnosing and monitoring patients with inherited metabolic disorders. Current methods are hindered by long preparative and/or analysis times, expensive reagents, and often suboptimal performance characteristics. To overcome these challenges, a improved method for amino acid analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed and validated. Samples were deproteinized with sulfosalicylic acid and supernatants diluted with tridecafluoroheptanoic acid. Chromatographic separation of amino acids occurred using two columns, with conditions favoring resolution of isobaric compounds and minimizing ion suppression. Eluted compounds were detected by selective reaction monitoring, and quantitated by relating peak areas of amino acids to externally run standards. Validation studies evaluated linearity, within- and between-run imprecision, lower limits of detection and quantification for 33 amino acids, and correlation with the Biochrom 30 Amino Acid Analyzer. Total run time including re-equilibration was 15min per sample. Within-run precision averaged 2.8% for all compounds, with an average linear correlation coefficient of 0.995. The majority of compounds were reliably quantitated at ≤0.1μM. Between-run precision averaged 4.0%. Results showed excellent correlation with the Biochrom 30 amino acid analyzer with an average overall correlation of 0.908. We conclude that our method is extremely sensitive, specific and reproducible and represents an improvement over other currently available technologies.

    View details for DOI 10.1016/j.jchromb.2013.11.017

    View details for Web of Science ID 000329770300027

    View details for PubMedID 24316529

  • Liver-directed adeno-associated virus serotype 8 gene transfer rescues a lethal murine model of citrullinemia type 1. Gene therapy Chandler, R. J., Tarasenko, T. N., Cusmano-Ozog, K., Sun, Q., Sutton, V. R., Venditti, C. P., McGuire, P. J. 2013; 20 (12): 1188-91


    Citrullinemia type 1 (CTLN1) is an autosomal recessive disorder of metabolism caused by a deficiency of argininosuccinate synthetase. Despite optimal management, CTLN1 patients still suffer from lethal metabolic instability and experience life-threatening episodes of acute hyperammonemia. A murine model of CTLN1 (fold/fold) that displays lethality within the first 21 days of life was used to determine the efficacy of adeno-associated viral (AAV) gene transfer as a potential therapy. An AAV serotype 8 (AAV8) vector was engineered to express the human ASS1 cDNA under the control of a liver-specific promoter (thyroxine-binding globulin, TBG), AAV8-TBG-hASS1, and delivered to 7-10 days old mice via intraperitoneal injection. Greater than 95% of the mice were rescued from lethality and survival was extended beyond 100 days after receiving a single dose of vector. AAV8-TBG-hASS1 treatment resulted in liver-specific expression of hASS1, increased ASS1 enzyme activity, reduction in plasma ammonia and citrulline concentrations and significant phenotypic improvement of the fold/fold growth and skin phenotypes. These experiments highlight a gene transfer approach using AAV8 vector for liver-targeted gene therapy that could serve as a treatment for CTLN1.

    View details for DOI 10.1038/gt.2013.53

    View details for PubMedID 24131980

    View details for PubMedCentralID PMC3855546

  • Targeting proximal tubule mitochondrial dysfunction attenuates the renal disease of methylmalonic acidemia PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Manoli, I., Sysol, J. R., Li, L., Houillier, P., Garone, C., Wang, C., Zerfas, P. M., Cusmano-Ozog, K., Young, S., Trivedi, N. S., Cheng, J., Sloan, J. L., Chandler, R. J., Abu-Asab, M., Tsokos, M., Elkahloun, A. G., Rosen, S., Enns, G. M., Berry, G. T., Hoffmann, V., DiMauro, S., Schnermann, J., Venditti, C. P. 2013; 110 (33): 13552-13557


    Isolated methylmalonic acidemia (MMA), caused by deficiency of the mitochondrial enzyme methylmalonyl-CoA mutase (MUT), is often complicated by end stage renal disease that is resistant to conventional therapies, including liver transplantation. To establish a viable model of MMA renal disease, Mut was expressed in the liver of Mut(-/-) mice as a stable transgene under the control of an albumin (INS-Alb-Mut) promoter. Mut(-/-);Tg(INS-Alb-Mut) mice, although completely rescued from neonatal lethality that was displayed by Mut(-/-) mice, manifested a decreased glomerular filtration rate (GFR), chronic tubulointerstitial nephritis and ultrastructural changes in the proximal tubule mitochondria associated with aberrant tubular function, as demonstrated by single-nephron GFR studies. Microarray analysis of Mut(-/-);Tg(INS-Alb-Mut) kidneys identified numerous biomarkers, including lipocalin-2, which was then used to monitor the response of the GFR to antioxidant therapy in the mouse model. Renal biopsies and biomarker analysis from a large and diverse patient cohort ( identifier: NCT00078078) precisely replicated the findings in the animals, establishing Mut(-/-);Tg(INS-Alb-Mut) mice as a unique model of MMA renal disease. Our studies suggest proximal tubular mitochondrial dysfunction is a key pathogenic mechanism of MMA-associated kidney disease, identify lipocalin-2 as a biomarker of increased oxidative stress in the renal tubule, and demonstrate that antioxidants can attenuate the renal disease of MMA.

    View details for DOI 10.1073/pnas.1302764110

    View details for Web of Science ID 000323069200075

    View details for PubMedID 23898205

    View details for PubMedCentralID PMC3746875

  • A new LC-MS/MS method for the clinical determination of reduced and oxidized glutathione from whole blood. Journal of chromatography. B, Analytical technologies in the biomedical and life sciences Moore, T., Le, A., Niemi, A., Kwan, T., Cusmano-Ozog, K., Enns, G. M., Cowan, T. M. 2013; 929: 51-55


    Reduced levels of glutathione (γ-glutamylcysteinylglycine, GSH) and the ratio of GSH to glutathione disulfide (GSSG) can serve as important indicators of oxidative stress and disease risk. Measured concentrations of GSH and GSSG vary widely between laboratories, largely due to the instability of GSH during sample handling and variables arising from different analytical methods. We have developed a simple and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for measuring whole blood GSH and GSSG that minimizes preanalytic and analytic variability, reliably eliminates interference from ion suppression, and can easily be implemented in clinical laboratories. Samples were deproteinized with sulfosalicylic acid (SSA) and derivatized with N-ethylmaleimide (NEM) in a single preparative step, and the resulting supernatants combined with stable-isotope internal standards (GSH-(13)C, (15)N-NEM and GSSG-(13)C,(15)N), subjected to chromatographic separation using a Hypercarb column, and analyzed by MS/MS in the positive-ion mode. Results showed excellent linearity for both GSH and GSSG over the ranges of physiologic normal, with inter- and intra-assay CV's of 3.1-4.3% and accuracy between 95% and 101%. The lower limits of detection (LLOD) were 0.4μM for GSH and 0.1μM for GSSG and the lower limits of quantitation (LLOQ) were 1.5μM for GSH and 0.1μM for GSSG. Derivatized samples are stable for at least 3 years when stored at -80°C, and underivatized samples for at least 24h at either 4°C or room temperature. Reference intervals were determined for 59 control samples, and were (mean±SD): GSH 900±140μM; GSSG 1.17±0.43μM; GSH/GSSG 880±370.

    View details for DOI 10.1016/j.jchromb.2013.04.004

    View details for PubMedID 23660247

  • Outcome of infants diagnosed with 3-methyl-crotonyl-CoA-carboxylase deficiency by newborn screening MOLECULAR GENETICS AND METABOLISM Arnold, G. L., Salazar, D., Neidich, J. A., Suwannarat, P., Graham, B. H., Lichter-Konecki, U., Bosch, A. M., Cusmano-Ozog, K., Enns, G., Wright, E. L., Lanpher, B. C., Owen, N. N., Lipson, M. H., Cerone, R., Levy, P., Wong, L. C., Dezsofi, A. 2012; 106 (4): 439-441


    3-Methyl CoA carboxylase (3-MCC) deficiency is an inborn error of metabolism in the catabolism of the amino acid leucine. Original reports suggested this disorder was associated with significant neurological and biochemical effects. However newborn screening has identified a higher than expected incidence of this disorder with apparent normal outcome in most cases.A retrospective analysis of thirty-five cases of 3-MCC deficiency identified by newborn screening and diagnosed by enzyme or molecular analysis.There was a strong inverse correlation between initial C5OH level and residual enzyme activity. A few reports of hypoglycemia, ketosis, poor feeding/failure to thrive or fasting intolerance were reported, but there was no clear relationship between symptoms and residual enzyme activity. Developmental outcome included several children with mental retardation (including one with Down syndrome and one with schizencephaly) and two with Autism Spectrum disorders but there was no apparent relationship to residual enzyme activity. Free carnitine deficiency was relatively common.Although residual enzyme activity was clearly related to metabolite elevation, there was no apparent relationship with other measures of outcome. The number of reports of neurologic abnormalities or metabolic symptoms (poor feeding, hypoglycemia, fasting intolerance, etc.) is concerning, but the significance is unclear in this retrospective sample.

    View details for DOI 10.1016/j.ymgme.2012.04.006

    View details for Web of Science ID 000307322100007

    View details for PubMedID 22658692

  • The role of vanin-1 and oxidative stress-related pathways in distinguishing acute and chronic pediatric ITP BLOOD Zhang, B., Lo, C., Shen, L., Sood, R., Jones, C., Cusmano-Ozog, K., Park-Snyder, S., Wong, W., Jeng, M., Cowan, T., Engleman, E. G., Zehnder, J. L. 2011; 117 (17): 4569-4579


    Pediatric immune thrombocytopenia (ITP) is usually self-limited. However, approximately 20% of children develop chronic ITP, which can be associated with significant morbidity because of long-term immunosuppression and splenectomy in refractory cases. To explore the molecular mechanism of chronic ITP compared with acute ITP, we studied 63 pediatric patients with ITP. Gene expression analysis of whole blood revealed distinct signatures for acute and chronic ITP. Oxidative stress-related pathways were among the most significant chronic ITP-associated pathways. Overexpression of VNN1, an oxidative stress sensor in epithelial cells, was most strongly associated with progression to chronic ITP. Studies of normal persons demonstrated VNN1 expression in a variety of blood cells. Exposure of blood mononuclear cells to oxidative stress inducers elicited dramatic up-regulation of VNN1 and down-regulation of PPARγ, indicating a role for VNN1 as a peripheral blood oxidative stress sensor. Assessment of redox state by tandem mass spectrometry demonstrated statistically significant lower glutathione ratios in patients with ITP versus healthy controls; lower glutathione ratios were also seen in untreated patients with ITP compared with recently treated patients. Our work demonstrates distinct patterns of gene expression in acute and chronic ITP and implicates oxidative stress pathways in the pathogenesis of chronic pediatric ITP.

    View details for DOI 10.1182/blood-2010-09-304931

    View details for PubMedID 21325602

  • Dopa-responsive dystonia presenting as delayed and awkward gait PEDIATRIC NEUROLOGY Cheyette, B. N., Cheyette, S. N., Cusmano-Ozog, K., Enns, G. M. 2008; 38 (4): 273-275


    Dopa-responsive dystonia is a hereditary disease characterized by inadequate dopamine production. Autosomal-dominant cases result from mutations in the GCH1 gene, encoding guanosine triphosphate (GTP)-cyclohydrolase 1. The most common presenting manifestation is dystonia of a lower extremity, often worsening late in the day. The onset and clinical severity are variable, sometimes even within a single family. Gender effects on allele penetrance have been reported. We present a male toddler with dopa-responsive dystonia caused by an autosomal-dominant GCH1 mutation. Three other family members were also found to carry the mutation, with widely different functional consequences.

    View details for DOI 10.1016/j.pediatrneurol.2007.12.005

    View details for Web of Science ID 000254646800009

    View details for PubMedID 18358407

  • Progressive and symmetric supraorbital hyperostosis with bony and soft tissue overgrowth in an Ethiopian female: A newly recognized overgrowth syndrome? AMERICAN JOURNAL OF MEDICAL GENETICS PART A Adam, M. P., Kobori, J. A., Cusmano-Ozog, K., Chen, K. M., Hoyme, H. E. 2008; 146A (5): 543-547


    We report on an Ethiopian female with generalized overgrowth of postnatal onset accompanied by progressive and symmetric overgrowth of skeletal and soft tissues. Her phenotype consisted of progressive and symmetric overgrowth of the supraorbital ridges, glabella, occiput, cervical spine, and distal phalanges of all extremities, but particularly the 3rd and 4th digits. She also has overgrowth of soft tissues of the posterior neck (thought to be fatty in origin), alveolar hyperplasia, and overgrowth of the skin comprising the areola and umbilicus. Other clinical findings included obstructive sleep apnea and normal intelligence. A genetic workup of extended banding chromosome analysis and chromosomal microarray were normal, as were PTEN and FNLA mutation analyses. Histologic examination of the excised supraorbital ridges demonstrated normal bone. However, the bone began to regrow in a symmetric fashion within 3 months of removal. This patient's phenotype is at variance with any known overgrowth syndrome.

    View details for DOI 10.1002/ajmg.a.32166

    View details for Web of Science ID 000253650200002

    View details for PubMedID 18241057

  • 22q13.3 deletion syndrome: A recognizable malformation syndrome associated with marked speech and language delay AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS Cusmano-Ozog, K., Manning, M. A., Hoyme, H. E. 2007; 145C (4): 393-398


    The 22q13.3 deletion syndrome is a recognizable malformation syndrome associated with developmental delay, hypotonia, delayed or absent speech, autistic-like behavior, normal to accelerated growth and dysmorphic facies. The prevalence of this disorder is unknown, but it is likely under-diagnosed. Age at diagnosis has varied widely, from cases diagnosed prenatally to 46 years. Males and females are equally affected. The distal 22q deletion can be detected occasionally by routine or high resolution chromosome analysis; however, the majority of cases are detected by FISH analysis, associated with deletion of the ARSA (control) probe when performing a FISH analysis for the velocardiofacial syndrome (del 22q11.2). The 22q13.3 deletion syndrome can accompany a simple chromosome deletion, an unbalanced translocation, or a ring chromosome. Primary care physicians, in addition to numerous specialists, play an important role in caring for patients with this disorder. Although the dysmorphic features observed in this condition are nonspecific, it is an important consideration in the differential diagnosis of children with developmental delay, hypotonia, marked speech and language disability, autistic-like features, multiple minor anomalies, and normal growth and head circumference.

    View details for DOI 10.1002/ajmg.c.30155

    View details for Web of Science ID 000251230300009

    View details for PubMedID 17926345