Evaluating the association of bone morphogenetic protein 4-V152A and SIX homeobox 6-H141N polymorphisms with congenital cataract and microphthalmia in Western Indian population

BACKGROUND: Congenital cataract and microphthalmia are highly heterogeneous congenital eye disorders that affect normal vision. Although mutation in several genes has been shown to cause congenital cataract and microphthalmia, genetic studies associating single-nucleotide polymorphisms with these conditions is scarce. Hence, the present study aims to investigate the association of bone morphogenetic protein 4 (BMP4)-V152A (rs17563), and SIX homeobox 6 (SIX6)-H141N (rs33912345) polymorphisms with congenital cataract and microphthalmia in Western Indian cohorts. MATERIALS AND METHODS: BMP4-V152A and SIX6-H141N were genotyped in 561 participants comprising of 242 congenital cataracts, 52 microphthalmia, and 267 controls using polymerase chain reaction (PCR) and allele specific oligonucleotide (ASO)-PCR method, respectively. RESULTS: The frequency of BMP4- 152A was found to be significantly different between the cases and controls (Odds ratio (OR) 95% confidence interval [CI] = 1.4 [1.03–1.76], P = 0.0275). The frequency of BMP4- 152AA genotype was found to be significantly higher in congenital cataract cases as compared to controls (OR [95% CI] = 2.1 [1.14–3.67], P = 0.0154. The V-N haplotype of BMP4-V152A and SIX6-H141N was found to have a protective effect toward congenital cataract (OR [95% CI] = 0.72 [0.56–0.94], P = 0.0163) and microphthalmia (OR [95% CI] = 0.63 [0.40–1.01, P = 0.0541). CONCLUSIONS: The BMP4- 152AA genotype might play role in the causation of congenital cataract, whereas BMP4-SIX6 V-N haplotype might play a protective role toward the development of congenital cataract and microphthalmia.