Distribution of Six Polymorphisms in Two Communities with a Historical High Incidence of Diabetes and Obesity in Yucatan, Mexico

Aims: Maya ancestry populations from Yucatan have exhibited a high prevalence of diabetes and obesity; consequently, the aim of this study was to determine the allelic and genotype frequencies of six polymorphisms associated with diabetes and obesity in two Maya populations.

Place and Duration of Study: Department of Genetics and Molecular Biology, Centro de Investigación y de Estudios Avanzados del IPN; Laboratorios de Genética y Hematología, Centro de Investigaciones Regionales “Dr. Hideyo Noguchi”, Universidad Autónoma de Yucatán between September 2014 and March 2016.

Methodology: Healthy individuals with Maya ancestry were recruited in small rural and urban communities from Yucatan. Six polymorphisms present in five genes (PPARGC1A, NRF1, SLC30A8, ADRA2A and UCP3) were genotyped using TaqMan assays. Linkage disequilibrium analysis was performed for rs13266634 and rs11558471 (SLC30A8).

Results: The observed frequencies in the small rural community (SRC) and Merida were in Hardy Weinberg equilibrium. Frequencies of five polymorphisms (rs8192678, rs1882095, rs13266634, rs11558471 and rs3781907) correlated with 1000 genomes project data, furthermore, statistical analysis did not reveal a significant difference between genotype frequencies of the SRC and Merida populations. Contrary, frequencies from Mexicans living in Los Angeles compared with frequencies obtained in Yucatan (SRC and Merida) indicated significant difference on genotype frequencies in the ADRA2A gene (P-value= .017). The polymorphisms rs13266634 and rs11558471 in the SLC30A8 gene displayed strong linkage disequilibrium (D’= 0.96), displaying frequencies of 0.725, 0.255, and 0.015 for haplotypes C-A, T-G, and C-G respectively.

Conclusion: Distribution of A allele in rs553668 (ADRA2A) in the Yucatan populations was higher than the frequency reported for Mexicans from LA, Americans, Europeans, and Africans. This finding could be related to blood pressure levels in the Maya populations. Additionally, a high frequency of C-A haplotype (rs13266634 and rs11558471) in the SLC30A8 gene could be associated with an increased risk of diabetes and obesity in these populations.