Common genetic link between metabolic syndrome components and senile cataract

Relationship between cataract and metabolic syndrome (MetS) is well established, but genetic link remains to be explored. D2S439 at 2q37 linked with QTL controlling visceral fat was investigated for its association with senile cataract. Two hundred and twenty-seven subjects including 119 cataract cases were genotyped for D2S439, tetra nucleotide repeat marker. Statistical tools assessed the association of marker's allele with anthropometric, clinical and oxidation stress parameters. Cases with longer allele ≥ (CTAT)(12) repeats, differed significantly from controls (0.77 vs. 0.58, p < 0.0001). Cases with at least one longer allele had higher waist circumference (50% vs. 15%, p = 0.0090), hyper-triglyceridemia (28% vs. 11%), hypo-HDL cholesterolemia (80% vs. 74%) and high diastolic blood pressure (37% vs. 26%) when compared to cases bearing the shorter allele. Cataract subjects with at least one longer allele had significantly raised lipid peroxidation levels (p = 0.0095) and showed an increased risk for cataract (OR = 5.86, CI(95%) = 1.49-23.11, p = 0.0114) after controlling for dependent variables. This exploratory study suggests that presence of even a single longer allele of D2S439 is associated with both cataract and MetS components in Asian Indians, unraveling the existence of a shared genetic locus.