MGEA5-14 polymorphism and type 2 diabetes in Mexico City

A family-based study has recently reported that a variant located in intron 10 of the gene MGEA5 increases susceptibility to Type 2 Diabetes (T2D). We evaluated the distribution of this SNP in a sample of T2D patients (N = 271) and controls (N = 244) from Mexico City. The frequency of the T allele was higher in the cases (2.6%) than in the controls (1.8%). After adjusting for age, sex, BMI, education, and individual ancestry the odds ratio was 1.60 but the 95% confidence interval was wide and overlapped 1 (0.52-4.86, P-value : 0.404). In order to characterize the distribution of the MGEA5-14 polymorphism in the relevant parental populations, we genotyped this variant in European (and European Americans), West African, and Native American samples. The T-allele was present at a frequency of 2.3% in Spain, 4.2% in European Americans, and 13% in Western Africans, but was absent in two Native American samples from Mexico and Peru. Given the low frequency of the T-allele, further studies using large sample sizes will be required to confirm the role of this variant in T2D.