Association of IFN-g+874(T/A) polymorphism with female patients of age-related cataracts

Abstract

Aim:Exposure to UV light is the major risk factor in the development of age-related cataract (ARC). UV filters produced during tryptophan catabolism maintain the transparency of the lens and protect retina from photo damage. Indoleamine 2, 3-dioxygenase (IDO), the first rate-limiting enzyme in the tryptophan catabolism, is up regulated by interferon-gamma (IFN-g) which harbors single nucleotide polymorphisms (SNPs). The T allele of SNP at +874 position of the IFN-g is known to be associated with the up regulation of IDO than the allele A. Hence, we attempted to study the IFN-g+874(T/A) polymorphism for its association with ARCs.Materials and Methods:A total of 680 cataract cases [199 nuclear (NC), 175 cortical (CC), 174 posterior subcapsular (PSC), and 132 mixed types (MT)] and 210 healthy controls were genotyped for +874(T/A) polymorphism using amplification refractory mutation system-polymerase chain reaction on 2% agarose gel stained with ethidium bromide.Results:There was increased risk for CC and PSC when the patients happened to be females, with low body mass index and with early onset. Considering the IFN-g polymorphism, a high risk was observed for CC and PSC in female patients of AA genotype with significant protection for those with TT genotypes.Conclusion:Present results indicate that +874(T/A) polymorphism may be considered as one of the biomarkers to distinguish between the CC and PSC types of cataracts for risk estimations. The study appears to be the first of its kind reporting an association of IFN-g+874(T/A) polymorphism with ARCs.