Association of the rs7903146 and rs12255372 polymorphisms in the TCF7L2 gene with type 2 diabetes in a population from northeastern Brazil

Abstract

ABSTRACT. Approximately 200 million people suffer from type 2 diabetes (T2D) worldwide, and the rapid increase in the prevalence of this disease is likely a result of multiple environmental factors, such as increased food intake and decreased physical activity in genetically predisposed individuals. Different population studies have demonstrated a strong association of two polymorphic variations in the TCF7L2 gene, the noncoding single nucleotide polymorphisms (SNPs) rs7903146 (C/T) and rs12255372 (G/T), with T2D. Herein, we analyzed the association of these SNPs with T2D in a population from northeastern Brazil. Our results showed that the genotype and allele frequencies in TCF7L2 rs7903146 and rs12255372 were similar in the patient and control groups (P > 0.05). In addition, the allele frequencies were not significantly associated with T2D risk [rs7903146: odds ratio (OR) = 0.95, 95% confidence interval (CI) = 0.52-1.76, P = 1.00, and rs12255372: OR = 1.38, 95%CI = 0.72-2.62, P = 0.41]. These data suggest that the TCF7L2 SNPs rs7903146 and rs12255372 may not significantly contribute to T2D susceptibility in this population. However, our results may reflect the small number of subjects. Alternatively, these results may be attributable to specific ethnic effects, as most of the previously reported associations were demonstrated with predominantly European populations. To reach a definitive conclusion on the role of such gene variants for T2D in mixed populations, additional efforts are necessary to replicate this study with larger populations from areas with more ethnic heterogeneity.

Design of an allele-specific PCR assay to genotype the rs12255372 SNP in a pilot study of association between common TCF7L2 polymorphisms and type 2 diabetes in Venezuelans

“…(26) and Barros and cols. (27) did not find association of the TCF7L2 rs12255372 SNP with T2DM in Brazilian populations. Moreover, Franco and cols.…”

“…However, Barros and cols. (27) failed to find an association of this variant with T2DM in northeastern populations from Brazil; while, Parra and cols. (30) also reported no association between the rs7903146 SNPs and T2DM in a replicate case-control study conducted in Mexico City.…”

“…Moreover, among Latin American countries there are only reports on the association of TCF7L2 polymorphisms and T2DM from Colombia (23), Brazil (24)(25)(26)(27)(28) and Mexico (9,(29)(30)(31)(32). Latin American populations are characterized by high socioeconomic and genetic heterogeneity with varying degrees of ancestral population proportions from country to country, thus more studies are needed exploring the basis of T2DM susceptibility from these mixed populations.…”

Association between transcription factor 7-like 2 genetic polymorphisms and development of type 2 diabetes in a Chinese population

“…To date, several studies have tested the association between TCF7L2 genetic variations and risk of developing type 2 diabetes mellitus (Assmann et al, 2014;Barros et al, 2014;OuhaibiDjellouli et al, 2014;Guewo-Fokeng et al, 2015;Nanfa et al, 2015;Yang et al, 2015;Yao et al, 2015). Assmann et al (2014), Guewo-Fokeng et al (2015), and Ouhaibi-Djellouli et al (2014) conducted investigations to assess the role of the TCF7L2 rs7903146 polymorphism in the pathogenesis of this disease, reporting that this sequence variant is associated with susceptibility to type 2 diabetes mellitus in Caucasians.…”

“…TCF7L2 expression is related to its proposed function in insulin secretion. Several previous studies have examined the role of the TCF7L2 rs7903146 polymorphism in the development of type 2 diabetes mellitus, but their results have been inconclusive (Assmann et al, 2014;Barros et al, 2014;Allahdini et al, 2015;GuewoFokeng et al, 2015;Liu et al, 2015;Nanfa et al, 2015;Yao et al, 2015;Yang et al, 2015). In this study, we conducted a hospital-based case-control investigation to evaluate the relationship between TCF7L2 rs7903146 and risk of developing type 2 diabetes mellitus in a Chinese population.…”