Genotype association of VEGF polymorphism rs2010963 with Strabismus in a Pakistani cohort

Purpose: This study was conducted to investigate the associations between specific genetic variation in VEGF and the prevalence of strabismus, with particular focus on VEGF polymorphism rs2010963 and whether presence of GG phenotype increases the odds of strabismus compared to GC or CC allele in a Pakistani cohort. Patients and methods: Blood samples from 43 strabismus patients and 170 normal controls (taken from an already published study from our group). Genotyping of the selected single nucleotide polymorphism (SNP) was carried out using polymerase chain reaction restriction fragment length polymorphism (PCR RFLP) for 43 samples of strabismus. Genotype and allele frequencies were then computed for all patients. Logistic regression was used to evaluate the association between the rs2010963 genotype and the risk of strabismus. A p value of < 0.05 was considered statistically significant. Results: Of the 43 strabismus patients, 27 (66%) had exotropia, followed by esotropia in 14 patients (34%). Their genotype frequency included 24 (56%) patients with the GG genotype, 14 (33%) with the GC genotype, and 5 (12%) with the CC genotype. Among the 170 normal controls, 50 (29%) had the GG genotype, 60 (35%) had the GC genotype, and 60 (35%) had the CC genotype. Individuals with the GG phenotype had significantly higher odds of having strabismus compared to those with CC genotype (OR = 5.76, 95% CI [2.05, 16.20], p = 0.0009). GG phenotype was also associated with higher odds to those with GC phenotype, but the result was not statistically significant (OR = 2.06 [0.96, 4.39], p = 0.062). Conclusion: This study explored the association of VEGFA polymorphism rs2010963 and strabismus in a Pakistani cohort. There is a higher prevalence of the GG genotype amongst patients with strabismus compared to normal controls, and a significant association between rs2010963 and strabismus.