p.S45G mutation at a conserved phosphorylation site of αA-crystallin in juvenile cortical cataract

Abstract

Abstract Purpose To identify the potential genetic cause in a patient diagnosed with juvenile cortical cataract. Observations: A young patient diagnosed with cortical cataract by ophthalmologic examination was recruited for the current study. DNA isolation was done followed by resequencing of all exons and exon-intron boundaries of 3 genes CRYAA, CRYABandCRYBB1, using intron specific primers. A mutation in CRYAA gene in heterozygous conditiong.44589342A > G (p.S45G), was identified in the patient. This mutation was predicted to be disease causing by Mutation Taster and other prediction tools. In-silico study revealed that this position (S45) was evolutionary conserved and mutation altered phosphorylation pattern of αA-crystallin as serine is the site of phosphorylation. Furthermore, this variant was absent in 130 unrelated healthy controls from this population suggesting it to be a disease-causing mutation. Conclusion and importance: The αA-crystallin mutation (p.S45G) causes juvenile cortical cataract in the patient due to discrepancy in phosphorylation pattern. This mutation is first time reported in juvenile cataract and happened to be the second mutation identified in CRYAA gene responsible for juvenile cataract.