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Medical Genetics and Genomic Medicine Training Program

Senior Clinician

Office of the Clinical Director

Associate Investigator

National Human Genome Research institute


M.D., Tashkent Pediatric Medical Institute, Uzbekistan


Dr. Shchelochkov is a board-certified pediatrician, clinical geneticist and medical biochemical geneticist, and is currently an associate investigator at NHGRI. After his early pediatrics training at the University of Iowa and genetics training at Baylor College of Medicine, Dr. Shchelochkov was a tenure-track assistant professor within the Pediatrics Department and Division of Genetics at the University of Iowa Hospitals and Clinics. He has been part of the NHGRI research community since 2015, starting as a staff clinician. Until recently, he was an associate research-physician studying many aspects of organic acidemias. In 2021, NHGRI appointed Dr. Shchelochkov as the new Director of Clinical and Laboratory Residencies and Fellowships. Dr. Shchelochkov is an author and a co-author on more than 60 peer-reviewed publications and book chapters.

Scientific Summary

Dr. Shchelochkov’s clinical research has focused on understanding the natural history of and novel therapeutic approaches to metabolic disorders. In 2006, he joined the lab of Dr. Brendan Lee, Baylor College of Medicine, where he studied the natural history of urea cycle disorders including argininosuccinic aciduria. By combining clinical and biochemical studies, he and his colleagues demonstrated beneficial effect of combining protein reduction and nitrogen scavenging to achieve better outcomes in patients with urea cycle disorders. Through national and international collaborations, Dr. Shchelochkov helped improve diagnostics and expand understanding of the natural history by describing novel aspects of urea cycle disorders, including a hyperammonemic syndrome after gastric bypass, expanded the spectrum of molecular genetics of CPS1 and OTC deficiencies, and published a clinical series documenting primary liver cancer in urea cycle disorders.

After joining Dr. Venditti’s lab at NHGRI, Dr. Shchelochkov implemented a new natural history protocol dedicated to the studies of propionic acidemia. This protocol-based study enabled novel insights into the spectrum of clinical complications including the prevalence and severity of chronic kidney disease, short stature, dilated cardiomyopathy and neurocognitive manifestations in patients with propionic acidemia. More recently, Dr. Shchelochkov and colleagues developed an analytic approach that uses machine learning to identify candidate biomarkers that correlate with clinical outcomes. This approach will support the development of novel genomic therapies in propionic acidemia, specifically systemic AAV gene therapy, a lead indication for the Platform Vector Gene Therapy (PaVe-GT) program. Currently, Dr. Shchelochkov works on extending the machine-learning paradigm to other rare diseases, where the number of participants is small, but disease classification is crucial, and discovery of biomarkers is required.


Bi W *, Sapir T *Shchelochkov OA *, Zhang F, Withers M, Hunter JV, Levy T, Shinder V, Peiffer DA, Gunderson KL, Nezarati MM, Shotts VA, Amato SS, Savage SK, Harris DJ, Day-Salvatore D-L, Horner M, Lu X-Y, Sahoo T, Yanagawa Y, Beaudet AL, Cheung SW, Martinez S, Lupski JR, Reiner O. LIS1 increased expression affects human and mouse brain development. Nat Genet 41(2):168-77, 2009. PMCID: 4396744  *Joint first authors

Shchelochkov OA, Tang LY, Li F, Geraghty M, Lichter-Konecki U, Fernhoff PM, Copeland S, Reimschisel T, Cederbaum S, Lee B, Chinault AG, Wong L-J. High frequency detection of variable rearrangements and deletions at the OTC locus by oligonucleotide array CGH. Mol Genet Metab 96(3):97-105, 2009. PMCID: 19138872

Shaibani A*, Shchelochkov OA*, Wong L-J, Shinawi M. Mitochondrial neurogastrointestinal encephalopathy due to mutations in RRM2B. Arch Neurol 66(8):1028-32, 2009. PMCID: 2747647  *Joint first authors  Archives of Neurology is currently JAMA Neurology

Lee B, Rhead W, Diaz GA, Scharschmidt BF, Mian A, Shchelochkov O, Marier JF, Beliveau M, Mauney J, Dickinson K, Martinez A, Gargosky S, Mokhtarani M, Berry SA. Phase 2 comparison of a novel ammonia scavenging agent with sodium phenylbutyrate in patients with urea cycle disorders: safety, pharmacokinetics and ammonia control. Mol Genet Metab 100(3):221-8, 2010. PMID: 20382058

Shchelochkov OA, Li F-Y, Wang J, Zhan H, Towbin JA, Jefferies JL, Wong L-J, Scaglia F. Milder clinical course of Type IV 3-methylglutaconic aciduria due to a novel mutation in TMEM70. Mol Genet Metab 101(2-3):282-5, 2010. PMID: 20728387

Wang J, Shchelochkov OA, Häberle J, Li F-G, Zhan H, H Chen, Brundage EK, Parsley AN, Schmitt ES, Wong L-J. Carbamoyl phosphate synthetase 1 gene gross deletion detected by array CGH. Mol Genet Metab 102(1):103-6, 2011. PMCID: PMC4869965

Häberle J, Shchelochkov OA, Wang J, Katsonis P, Hall L, Reiss S, Eeds A, Willis A, Yadav M, Summar S, the Urea Cycle Disorders Consortium, Lichtarge O, Rubio V, Wong L-J, Summar M. Molecular defects in human Carbamoyl Phosphate Synthetase I: mutation update, diagnostic and protein structure considerations. Hum Mutat 32(6):579-89, 2011. PMCID: PMC4861085

Erez A, Nagamani SC, Shchelochkov OA, Premkumar MH, Campeau PM, Chen Y, Garg HK, Li L, Mian A, Bertin TK, Black JO, Zeng H, Tang Y, Reddy AK, Summar M, O'Brien WE, Harrison DG, Mitch WE, Marini JC, Aschner JL, Bryan NS, Lee B. Requirement of argininosuccinate lyase for systemic nitric oxide production. Nat Med 17(12):1619-26, 2011. PMCID: PMC3348956

Wilson JM, Shchelochkov OA, Gallagher RC, Batshaw ML. Hepatocellular carcinoma in a research subject with ornithine transcarbamylase deficiency. Mol Genet Metab 105(2):263-5, 2012. PMCID: PMC3273986

Nagamani SCS*, Campeau PM*, Shchelochkov OA*, Premkumar MH, Guse K, Brunetti-Pierri N, Chen Y, Sun Q, Tang Y, Palmer D, Reddy AK, Li L, Slesnick TC, Feig DI, Caudle S, Harrison D, Salviati L, Marini JC, Bryan NS, Erez A, Lee B. Nitric-oxide supplementation for treatment of long-term complications in argininosuccinic aciduria. Am J Hum Genet 90(5):836-46, 2012. PMCID: PMC3376491  *Joint first authors

Nagamani CSC*, Shchelochkov OA*, Mullins MA, Carter S, Lanpher BC, Sun Q, Kleppe S, Erez A, O’Brian Smith E, Marini J, “Members of the Urea Cycle Disorders Consortium”, Lee B. A randomized controlled trial to evaluate the effects of high-dose versus low-dose of arginine therapy on hepatic function tests in argininosuccinic aciduria. Mol Genet Metab 107(3):315-21, 2012. PMCID: PMC3483446  *Joint first authors

Fenves AZ, Shchelochkov OA, Mehta A. Hyperammonemic syndrome after roux-en-y gastric bypass. Obesity (Silver Spring) 23(4):746-9, 2015. PMID: 25754921

Manoli I, Myles J, Sloan JL, Shchelochkov OA, Venditti CP. A critical reappraisal of dietary practices in methylmalonic acidemia raises concerns about the safety of medical foods. Part 1: Isolated methylmalonic acidemias (MMA). Genet Med 18(4):386-95, 2016. PMCID: PMC4752925

Shchelochkov OA, Dickinson K, Scharschmidt BF, Lee B, Marino M, Le Mons C. Barriers to drug adherence in the treatment of urea cycle disorders: assessment of patient, caregiver and provider perspectives. Mol Genet Metab Rep 8:43-7, 2016. PMCID: PMC4963256

Magoulas PL*, Shchelochkov OA*, Bainbridge MN, Ben-Shachar S, Yatsenko S, Potocki L, Lewis RA, Searby C, Marcogliese AN, Elghetany MT, Zapata G, Hernández PP, Gadkari M, Einhaus D, Muzny DM, Gibbs RA, Bertuch AA, Scott DA, Corvera S, Franco LM. Syndromic congenital myelofibrosis associated with a loss-of-function variant in RBSN. Blood 132(6):658-662, 2018. PMCID: PMC6085991 *Joint first authors

Kho J, Tian X, Wong WT, Bertin T, Jiang MM, Chen S, Jin Z, Shchelochkov OA, Burrage LC, Reddy AK, Jiang H, Abo-Zahrah R, Ma S, Zhang P, Bissig KD, Kim JJ, Devaraj S, Rodney GG, Erez A, Bryan NS, Nagamani SCS, Lee BH. Argininosuccinate lyase deficiency causes an endothelial-dependent form of hypertension. Am J Hum Genet 103(2):276-87, 2018. PMCID: PMC6080833

Lea D, Shchelochkov O, Cleary J, Koehly LM. Dietary management of propionic acidemia: parent caregiver perspectives and practices J Parenter Enteral Nutr 43(3):434-7, 2019. PMCID: PMC6395508

Shchelochkov OA, Manoli I, Sloan JL, Ferry S, Pass A, Van Ryzen C, Myles J, Schoenfeld M, McGuire P, Rosing DR, Levin MD, Kopp JB, Venditti CP. Chronic kidney disease in propionic acidemia. Genet Med 21(12):2830-2835, 2019. PMCID: PMC7045176

Manoli I, Pass AR, Harrington EA, Sloan JL, Gagne J, McCoy S, Bell SL, Leitnerr  BP, Duckworth CJ, Fletcher LA, Cassimatis TM, Galaretta CI, Thurm A, Snow J, Van  Ryzin C, Ferry S, Ah Mew N, Shchelochkov OA, Chen KY, Venditti CP.  13C-propionate breath testing as a surrogate endpoint to assess efficacy of liver-directed therapies in methylmalonic acidemia (MMA). Genet Med 23(8):1522-33, 2021. PMCID: PMC8354855

Shchelochkov OA, Manoli I, Juneau P, Sloan JL, Ferry SF, Myles J, Schoenfeld M, Pass A, McCoy S, Ryzin CV, Wenger O, Mevin M, Zein W, Huryn L, Snow J, Chlebowski C, Thurm A, Kopp JB, Kong Y, Chen KY, Venditti CP.  Severity modeling of propionic acidemia using clinical and laboratory biomarkers. Genet Med 23(8):1534-42, 2021. PMCID: PMC8354856

Pangilinan F, Watkins D, Bernard D, Chen Y, Dong N, Wu Q, Ozel-Abaan H, Kaur M, Caggana M, Morrissey M, Browne ML, Mills JL, Van Ryzin C, Shchelochkov O, Sloan J, Venditti CP, Sarafoglou K, Rosenblatt DS, Kay DM, Brody LC. Probing the functional consequence and clinical relevance of CD320 p.E88del, a variant in the transcobalamin receptor gene. Am J Med Genet A 2022 Feb 2. PMID: 35107211

Medical Genetics and Genomic Medicine Training Program Staff

Don Hadley, M.S., C.G.C.
Don Hadley, M.S., C.G.C.
  • Program Coordinator
  • Office of Clinical Liaison
Holly Babcock
Holly Babcock, M.S, C.G.C.
  • Genetic Counselor
  • Skeletal Genomics Unit
Seyma Eroglu
Seyma Eroglu, M.D.
  • Clinical Fellow
  • Medical Genetics and Genomic Medicine Training Program
Crystal Hernandez Hernandez
Cristal Hernandez Hernandez, M.D.
  • Clinical Fellow
  • Medical Genetics and Genomic Medicine Training Program
Maria Fernanda Barros Perez
Maria Fernanda Barros Perez, M.D.
  • Clinical Fellow
  • Medical Genetics and Genomic Medicine Training Program

Last updated: July 8, 2024