Very-long-chain fatty acid acyl-CoA dehydrogenase deficiency in Belarus

Introduction. Very-long-chain fatty acid acyl-CoA dehydrogenase deficiency (VLCADD) is a rare inherited disorder of fatty acid oxidation caused by mutations in the ACADVL gene. The prevalence of VLCADD is 1:30,000 – 1:100,000. The severe form of the disease presents in the neonatal period or within the first months of life and is characterized by cardiomyopathy, hydropericardium, arrhythmia, hypotension, hepatomegaly and hypoglycemia. Moderate VLCADD manifests in the first year of life or in early childhood, its symptoms include hepatomegaly and episodes of hypoketotic hypoglycemia. In mild cases, the first signs of the disease such as muscle pain, exercise intolerance, episodes of rhabdomyolysis appear in adolescence or later.

Purpose. To study the spectrum of mutations in the ACADVL gene in patients with VLCADD in the Republic of Belarus

Patients and methods. The study group included patients with VLCADD identified during selective screening for mitochondrial betaoxidation of fatty acids and other metabolic defects by tandem mass spectrometry (TMS), and their family members (4 probands, 2 parents, and a child of an adult patient). Genetic testing was performed via high-throughput sequencing combined with Sanger sequencing.

Results and discussion. Probands 1 and 2 suffered from acute metabolic decompensation, cardiomyopathy, hepatomegaly at the age of 3 months; the proband 2 also had progressive muscle hypotonia and severe hypoglycemia. Both children died at the age of 3.5 and 7 months, respectively. Probands 3 and 4 underwent TMS at 14 months and 25 years. In proband 3, the disease manifested with liver damage, episodes of hypoglycemia, cardiomyopathy. Symptoms of myopathy predominated in patient 4. Proband 1 was found to have a homozygous deletion p.Leu201TrpfsTer39 (NM_000018.4 (ACADVL): c.532delC) in exon 7 of the ACADVL gene. Proband 2 had missense mutation p.Gly253Val (NM_000018.4 (ACADVL): c.758G>T) in exon 9 and the frameshift mutation p.Pro296ArgfsTer17 (NM_000018.4 (ACADVL): c.887_888delCT) in exon 11. In Proband 3 we found p.Arg366Cys substitution (NM_000018.4 (ACADVL): c.1096C>T, rs771874163) in exon 11 and nonsense mutation p.Arg615Ter (NM_000018.4 (ACADVL): c.1843C>T, rs1057520507) in exon 20. Proband 4 had two likely pathogenic variants in intron 8 and exon 15: NM_000018.4 (ACADVL): c.752+2delC and p.Lys507Glu (NM_000018.4 (ACADVL): c.1519A>G, rs1217344032). The patient’s father and son were found to be carriers c.752+2delC mutation, and the mother had p.Lys507Glu in a heterozygous state.

Conclusion. VLCADD is a relatively rare hereditary metabolic defect in Belarus. The disease is characterized by pronounced clinical polymorphism, significant genetic heterogeneity, and the presence of evident genotype-phenotype correlations. As a result of the study, a spectrum of mutations in the ACADVL gene was established in patients with VLCADD in the Republic of Belarus, new pathogenic and likely pathogenic variants (p.Leu201TrpfsTer39, p.Gly253Val, p.Pro296ArgfsTer17 and c.752+2delC) were discovered. These variants were not registered in open databases and not previously described in available published works on VLCADD.

1. Siu W.K., Mak C.M., Siu S.L. et al. Molecular diagnosis for a fatal case of very long-chain acyl-CoA dehydrogenase deficiency in Hong Kong Chinese with a novel mutation: a preventable death by newborn screening. Diagn Mol Pathol. 2012;21(3):184-7. doi:10.1097/PDM.0b013e31825554d0.

2. Hesse J., Braun C., Behringer S. et al. The diagnostic challenge in very-long chain acyl-CoA dehydrogenase deficiency (VLCADD). J Inherit Metab Dis. 2018;41(6):1169-1178. doi: 10.1007/s10545-0180245-5.

3. Olsen R.K., Dobrowolski S.F., Kjeldsen M. et al. High-resolution melting analysis, a simple and effective method for reliable mutation scanning and frequency studies in the ACADVL gene. J Inherit Metab Dis. 2010;33(3):247-60. doi: 10.1007/s10545-010-9101-y.

4. Wang B., Zhang Q., Gao A. et al. New ratios for performance improvement for identifying acyl-CoA dehydrogenase deficiencies in expanded newborn screening: a retrospective study. Front Genet. 2019;10:811. doi: 10.3389/fgene.2019.00811.

5. Andresen B.S., Olpin S., Poorthuis B.J. et al. Clear correlation of genotype with disease phenotype in very-long-chain acyl-CoA dehydrogenase deficiency. Am J Hum Genet. 1999;64(2):479-94. doi: 10.1086/302261.

6. Mathur A., Sims H.F., Gopalakrishnan D. et al. Molecular heterogeneity in very-long-chain acyl-CoA dehydrogenase deficiency causing pediatric cardiomyopathy and sudden death. Circulation. 1999;99(10):1337-43. doi: 10.1161/01.cir.99.10.1337.

7. Roe C.R., Sweetman L., Roe D.S. et al. Treatment of cardiomyopathy and rhabdomyolysis in long-chain fat oxidation disorders using an anaplerotic odd-chain triglyceride. J Clin Invest. 2002;110(2):259-69. doi: 10.1172/JCI15311

8. Schiff M., Mohsen A.W., Karunanidhi A. et al. Molecular and cellular pathology of very-long-chain acyl-CoA dehydrogenase deficiency. Mol Genet Metab. 2013;109(1):21-7. doi: 10.1016/j.ymgme.2013.02.002.

9. Miller M.J., Burrage L.C., Gibson J.B. et al. Recurrent ACADVL molecular findings in individuals with a positive newborn screen for very long chain acyl-coA dehydrogenase (VLCAD) deficiency in the United States. Mol Genet Metab. 2015;116(3):139-45. doi: 10.1016/j.ymgme.2015.08.01

10. Andresen B.S., Bross P., Vianey-Saban C. et al. Cloning and characterization of human very-long-chain acyl-CoA dehydrogenase cDNA, chromosomal assignment of the gene and identification in four patients of nine different mutations within the VLCAD gene. Hum Mol Genet. 1996;5(4):461-72. doi: 10.1093/hmg/5.4.461. Erratum in: Hum Mol Genet 1996 Sep;5(9):1390.

11. Smon A., Repic Lampret B., Groselj U. et al. Next generation sequencing as a follow-up test in an expanded newborn screening programme. Clin Biochem. 2018

12. Hahn S.H., Lee E.H., Jung J.W. et al. Very long chain acyl coenzyme A dehydrogenase deficiency in a 5-month-old Korean boy: identification of a novel mutation. J Pediatr. 1999;135(2 Pt 1):2503. doi: 10.1016/s0022-3476(99)70030-2.

13. Leslie N.D., Valencia C.A., Strauss A.W. et al. Very Long-Chain Acyl-Coenzyme A Dehydrogenase Deficiency. 2009 May 28 [Updated 2021 May 13]. In: Adam MP, Ardinger HH, Pagon RA, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2022. Available from: https://www.ncbi.nlm.nih.gov/books/NBK6816/

14. Serkova V.K. Metabolicheskaya kardiocitoprotekciya v terapii bol’nyh ishemicheskoj bolezn’yu serdca: rol’ parcial’nyh ingibitorov okisleniya zhirnyh kislot [Metabolic cardiocytoprotection in the treatment of patients with coronary heart disease: the role of partial inhibitors of fatty acid oxidation]. Racional’naya farmakoterapiya [Rational pharmacotherapy]. 2008;1(6). https://rpht.com.ua/ru/archive/2008/1%286%29/article-76/metabolicheskayakardiocitoprotekciya-v-terapii-bolnyh-ishemicheskoy-boleznyu-serdcarol-parcialnyh-ingibitorov-okisleniya-zhirnyh-kislot (In Russ.)

15. Pena L.D., van Calcar S.C., Hansen J. et al. Outcomes and genotypephenotype correlations in 52 individuals with VLCAD deficiency diagnosed by NBS and enrolled in the IBEM-IS database. Mol Genet Metab. 2016;118(4):272-81. doi: 10.1016/j.ymgme.2016.05.007.

16. Zhang R.-N., Li Y.-F., Qiu W.-J. et al. Clinical features and mutations in seven Chinese patients with very long chain acyl-CoA dehydrogenase deficiency. World Journal of Pediatrics, 2014;10(2), 119–125. doi:10.1007/s12519-014-0480-2.

17. Li X., Ma R., Liu Y. et al. One Potential Hotspot ACADVL Mutation in Chinese Patients with Very-long-chain Acyl-coenzyme A Dehydrogenase Deficiency. Clinica Chimica Acta. 2019 doi:10.1016/j.cca.2019.11.034.

18. Miller M.J., Burrage L.C. Gibson J.B. et al. Recurrent ACADVL molecular findings in individuals with a positive newborn screen for very long chain acyl-coA dehydrogenase (VLCAD) deficiency in the United States. Mol Genet Metab. 2015;116(3):139-45. doi: 10.1016/j.ymgme.2015.08.011.

19. Alhashem A., Mohamed S., Abdelraheem M, et al. Molecular and clinical characteristics of very-long-chain acyl-CoA dehydrogenase deficiency: A single-center experience in Saudi Arabia. Saudi Med J. 2020;41(6):590-596. doi: 10.15537/smj.2020.6.25131.