Abstract
The Mexican population is characterized by high and particular admixture, and the picture of variants associated with disease remains unclear. Here we investigated the distribution of single nucleotide polymorphisms (SNPs) in the Mexican population. We focused on two non-synonymous and three synonymous SNPs in the beta-2 adrenergic receptor gene (ADRB2), which plays key roles in energy balance regulation. These SNPs were genotyped in 2,011 Mexican Amerindians (MAs) belonging to 62 ethnic groups and in 1,980 geographically matched Mexican Mestizos (MEZs). The frequency distribution of all five ADRB2 variants significantly differed between MAs, MEZs, and other continental populations (CPs) from the 1000 Genomes database. Allele frequencies of the three synonymous SNPs rs1042717A, rs1042718A, and rs1042719C were significantly higher in Mexican individuals, particularly among MAs, compared to in the other analyzed populations (P<0.05). The non-synonymous ADRB2 Glu27 allele (rs1042714G), which is associated with several common conditions, showed the lowest frequency in MAs (0.03) compared to other populations worldwide. Among MEZs, this allele showed a frequency of 0.15, intermediate between that in MAs and in Iberians (0.43). Moreover, Glu27 was the only SNP exhibiting a geographic gradient within the MEZ population (from 0.22 to 0.11), reflecting admixed mestizo ancestry across the country. Population differentiation analysis demonstrated that Glu27 had the highest FST value in MAs compared with Europeans (CEU) (0.71), and the lowest between MAs and Japanese (JPT) (0.01), even lower than that observed between MAs and MEZs (0.08). This analysis demonstrated the genetic diversity among Amerindian ethnicities, with the most extreme FST value (0.34) found between the Nahuatls from Morelos and the Seris. This is the first study of ADRB2 genetic variants among MA ethnicities. Our findings add to our understanding of the genetic contribution to variability in disease susceptibility in admixed populations.
Highlights
The Mexican Mestizo (MEZ) population is one of the most genetically diverse populations worldwide due to the admixture between Native American, European, and African populations [1]
In addition to MEZs, the Mexican population includes a great diversity of Mexican Amerindians (MAs), who were the original settlers of Mexico
We investigated the level of differentiation (FST) of the five ADRB2 polymorphisms between MAs, MEZs, and the continental populations (CPs)
Summary
The Mexican Mestizo (MEZ) population is one of the most genetically diverse populations worldwide due to the admixture between Native American, European, and African populations [1]. Recent studies suggest that ethnic diversity may introduce genetic variations that can potentially generate inter-individual differences in disease susceptibility and therapeutic efficacy [6,7,8]. These findings could be explained within an evolutionary framework, in which the frequencies of specific alleles reflect ancient genetic adaptations that have shifted due to environment and lifestyle differences among human populations [9]. Most research in this field has been performed among Caucasians [7,10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
