TXNRD2 and CDKN2B-AS1 gene polymorphisms in patients with Primary Open-Angle Glaucoma

Abstract

Purpose :

Recent studies have demonstrated association between single nucleotide polymorphisms (SNPs) in TXNRD2 and CDKN2B-AS1 genes and primary open angle glaucoma (POAG) in some populations. This is the first study to determine the frequency of these SNPs in a Brazilian’s population with POAG.

Methods : We performed a retrospective, case-control study to confirm the association between the rs35934224 (TXNRD2) and rs7866783 (CDKN2B-AS1) and POAG in a population from the northeast region of Brazil. A total of 156 individuals were enrolled, being 87 cases with POAG (43 males and 44 females) and 73 controls (27males and 46 females) from the Recife Eye Institute. Mean age was 67,5 years for cases and 67,7 years for controls. Cases were primarily defined as individuals with at least one reliable visual field showing vision loss consistent with glaucoma or documented progression of optic nerve degeneration by OCT-Spectralis, with Cup-to-Disc ratio ≥0.7. Controls had CDR <0.6, IOP <17 mmHg and family history negative for glaucoma. Genomic DNA was isolated using commercially available kits and detection of the SNPs was done by Real Time PCR using TaqMan probes. Differences in the frequency distribution between the groups were analyzed using the chi-squared test or Fisher’s exact test when appropriate.

Results : Individuals with POAG had a higher frequency of the CC genotype (rs35934224) in the TXNRD2 gene than controls (71.0% vs. 61.1%, p=0.18). The C allele presented similar distribution (84.3% vs. 80.5%, p=0.38). Regarding the rs7866783 in the CDKN2B-AS1 gene, the GG genotype was more prevalent in individuals with POAG (67.8% vs. 63.0%, p=0.52). The G allele was equally distributed (82.1% vs. 78.7%, p=0.44).

Conclusions : No association was observed between the CC and GG risk genotypes in the TXNRD2 and CDKN2B-AS1 genes, respectively, with POAG in Brazilian patients. Further studies are needed to confirm these results in a larger cohort.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.