Mutation Analysis of GLDC, AMT and GCSH in Cataract Captive-bred Vervet Monkeys (Chlorocebus Aethiops)

Background: Non-ketotic hyperglycinaemia (NKH) is an autosomal recessive inborn error of glycine metabolism characterized by accumulation of glycine in body fluids and various neurological symptoms.

Methods: This study describes the first screening of NKH in cataract captive-bred vervet monkeys (Chlorocebus aethiops). Glycine dehydrogenase (GLDC), aminomethyltransferase (AMT) and glycine cleavage system H protein (GCSH) were prioritized.

Results: Mutation analysis of the complete coding sequence of GLDC and AMT revealed six novel single-base substitutions, of which three were non-synonymous missense and three were silent nucleotide changes.

Conclusion: Although deleterious effects of the three amino acid substitutions were not evaluated, one substitution of GLDC gene (S44R) could be disease-causing because of its drastic amino acid change, affecting amino acids conserved in different primate species. This study confirms the diagnosis of NKH for the first time in vervet monkeys with cataracts.