Autosomal recessive congenital cataract in captive-bred vervet monkeys (Chlorocebus aethiops)

Abstract

Background: The aim of the study was to evaluate the genetic predisposition of congenital cataract in a colony of captive-bred vervet monkeys.

Methods: Four congenital cataract genes: glucosaminyl (N-acetyl) transferase 2 (GCNT2), heat shock transcription factor 4 (HSF4), crystallin alpha A (CRYAA) and lens intrinsic membrane protein-2 (LIM2) were screened, sequenced and analysed for possible genetic variants in 36 monkeys. Gene expression was also evaluated in these genes.

Results: Fifteen sequence variants were identified in the coding regions of three genes (GCNT2, HSF4 and CRYAA). Of these variations, only three were missense mutations (M258V, V16I and S24N) and identified in the GCNT2 transcripts A, B and C, respectively, which resulted in a downregulated gene expression.

Conclusion: Although the three missense mutations in GCNT2 have a benign effect, a possibility exists that the candidate genes (GCNT2, HSF4 and CRYAA) might harbour mutations that are responsible for total congenital cataract.

Keywords: crystallin alpha A; glucosaminyl (N-acetyl) transferase 2; heat shock transcription factor 4; lens intrinsic membrane protein-2; non-human primates; sequence variants.