Hyperammonemia in Russia Due to Carbonic Anhydrase VA Deficiency Caused by Homozygous Mutation p.Lys185Lys (c.555G>A) of the CA5A Gene

Int J Mol Sci. 2022 Nov 30;23(23):15026. doi: 10.3390/ijms232315026.

Abstract

Hyperammonemia due to carbonic anhydrase VA deficiency (OMIM# 615751) is a rare, life-threatening hereditary disease caused by biallelic mutations in the CA5A gene, presenting as encephalopathic hyperammonemia of unexplained origin during the neonatal period and infancy. Here, we present a detailed description of a 5-year-old patient with the homozygous mutation p.Lys185Lys (c.555G>A) in the CA5A gene. This variant was previously described by van Karnebeek et al. in 2014 in a boy of Russian origin. We found a high frequency of carriers of this mutation in Russia; 1:213, which is 7 times higher than the expected frequency calculated based on data on Western European populations. Thus, targeted testing for the mutation p.Lys185Lys (c.555G>A) in the CA5A gene should be useful for early detection by selective screening in neonatal intensive care units.

Keywords: CA5A gene; carbonic anhydrase VA deficiency; hyperammonemia.

Publication types

  • Case Reports

MeSH terms

  • Child, Preschool
  • Homozygote
  • Humans
  • Hyperammonemia* / genetics
  • Infant, Newborn
  • Male
  • Maple Syrup Urine Disease*
  • Mutation
  • Neurotoxicity Syndromes*
  • White People

Grants and funding

The research was carried out within the state assignment of Ministry of Science and Higher Education of the Russian Federation for RCMG. The funder had no role in the design of the study or in the collection, analyses, and interpretation of data or in writing the manuscript or in the decision to publish the results.