Association of IGF1 polymorphisms with exotropia in a Pakistani cohort.

Purpose: Strabismus (STBMS) is a multifactorial ocular disorder in children that leads to misalignment of the eyes. Insulin-like growth factor 1 (IGF1) has been shown to be involved in the development of extraocular muscles and myopia; however, data are limited on the genetic associations of IGF1 with STBMS in Pakistan. Methods: Two hundred seventy-four STBMS cases and 272 unaffected controls were recruited, and their DNA was extracted. Two IGF1 single nucleotide polymorphisms, rs6214 and rs5742632, were genotyped using PCR-restriction fragment length polymorphism. Univariate logistic regression analysis was performed to determine the association of these single nucleotide polymorphisms with STBMS, and the results were adjusted for age and sex. In addition, 26 extraocular muscle tissues were collected from patients with STBMS undergoing squint correction surgery, along with 3 deceased control samples. IGF1 mRNA expression was measured by quantitative PCR; the Mann-Whitney U test was applied, and fold change was calculated. Logistic regression analysis was applied to determine the association of RNA expression and fold change with genotype. Results: Multivariate logistic regression analysis revealed that rs5742632 (odds ratio [95% confidence interval] = 1.05[1.01-1.06], p = 0.03) is associated with STBM. Moreover, rs6214 (1.03[1.01-1.05], p = 0.03) and rs5742632 (1.09[1.04-1.11], p = 0.04) were associated with exotropia. Statistically, no significant difference in IGF1 mRNA expression in the extraocular muscles between the STBMS cases and the controls was observed. Conclusions: IGF1 polymorphisms rs5742632 (A>G) and rs6214 (C>T) are plausible risk factors for the development of exotropia. However, the physiologic mechanism requires further evaluation.

Transcriptomic Analysis of Conserved Telomere Maintenance Component 1 (CTC1) and Its Association with Leukemia.

Telomere length (TEL) regulation is important for genome stability and is governed by the coordinated role of shelterin proteins, telomerase (TERT), and CST (CTC1/OBFC1/TEN1) complex. Previous studies have shown the association of telomerase expression with the risk of acute lymphoblastic leukemia (ALL). However, no data are available for CST association with the ALL. The current pilot study was designed to evaluate the CST expression levels in ALL. In total, 350 subjects were recruited, including 250 ALL cases and 100 controls. The subjects were stratified by age and categorized into pediatrics (1-18 years) and adults (19-54 years). TEL and expression patterns of CTC1, OBFC1, and TERT genes were determined by qPCR. The univariable logistic regression analysis was performed to determine the association of gene expression with ALL, and the results were adjusted for age and sex in multivariable analyses. Pediatric and adult cases did not reflect any change in telomere lengths relative to controls. However, expression of CTC1, OBFC1, and TERT genes were induced among ALL cases. Multivariable logistic regression analyses showed association of CTC1 with ALL in pediatric [ß estimate (standard error (SE)= -0.013 (0.007), p = 0.049, and adults [0.053 (0.023), p = 0.025]. The association of CTC1 remained significant when taken together with OBFC1 and TERT in a multivariable model. Furthermore, CTC1 showed significant association with B-cell ALL [-0.057(0.017), p = 0.002) and T-cell ALL [-0.050 (0.018), p = 0.008] in pediatric group while no such association was noted in adults. Together, our findings demonstrated that telomere modulating genes, particularly CTC1, are strongly associated with ALL. Therefore, CTC1 can potentially be used as a risk biomarker for the identification of ALL in both pediatrics and adults.

Association of IGF1 and VEGFA polymorphisms with diabetic retinopathy in Pakistani population.

AIMS: The incidence of microvascular complications, including diabetic retinopathy (DR), increases with duration of type 2 diabetes (T2D). Meta-GWAS have reported numerous single-nucleotide polymorphisms (SNPs) associated with T2D; however, no loci, achieving genome-wide significance has been reported for DR. Vascular endothelial growth factor A (VEGFA) and insulin-like growth factor 1 (IGF1) are considered as potential genetic candidates involved in T2D and DR progression. Moreover, the association of serum levels of these proteins with diabetes-related traits is controversial. Therefore, the current study was designed to evaluate the possible genetic predisposition and role of these circulating growth factors in serum in the pathophysiology of T2D and DR. METHODS: A cohort of 1126 individuals with T2D was collected including those without retinopathy (DNR = 573), non-progressive diabetic retinopathy (NPDR = 301) and progressive diabetic retinopathy (PDR = 252), and 348 healthy controls. Genomic DNA was isolated, and six SNPs: rs833061, rs13207351, rs1570360, rs2010963, rs5742632 and rs6214, were genotyped and results statistically analyzed. ELISA was performed on a subset of the samples to measure serum levels of IGF1 and VEGFA. RESULTS: The minor allele of rs6214 was associated with T2D [OR = 1.67 (95% CI 1.39-2.01, p = 4.9E-8)], rs13207351 was associated with NPDR [OR = 1.97 (95% CI 1.28-3.03, p = 9.0E-3)]when compared with DNR, and rs5742632 showed positive association with PDR [OR = 1.66 (95% CI 1.33-2.05, p = 1.0E-4)] compared to DNR. Lowered IGF1 serum levels were found to be associated with T2D, NPDR and PDR. CONCLUSIONS: IGF1 was found to increase the T2DM susceptibility as well as advanced DR, i.e., PDR, while VEGFA was found to be associated with early DR stage, i.e., NPDR.