Frequency of an allele of EDAR gene in totonacos at Sierra Norte of Puebla and mestizos from Mexico City

Abstract

A-receptor gene of ectodysplasin (WWTP) plays an important role in the development of certain organs, especially those of ectodermal nature. A nonsynonymous variants of WWTP gene (V370A, T1540C, rs3827760) is proprietary to Asia and America, where it likely reached a high frequency by positive selection. 1540C allele has recently been linked to the shovel-shaped teeth in human groups of Japan, where it was estimated that approximately 19 % of the population describes the phenotypic diversity of this trait. We studied 91 unrelated individuals from Totonac in the Sierra Norte de Puebla, as well as 53 mestizos of Mexico City, with the purpose to report gene frequencies of this polymorphism. Our results show significant differences (p < .01) of the 1540C allele frequency in the Totonac (.88) and mixed population (.48). These results are consistent with the higher 1540C allele frequencies observed in Northeast Asian populations and frequency in Native American populations. Moreover, we noted that the data are not in Hardy-Weinberg equilibrium in the Totonac population, suggesting inbreeding process in a sector of the community as reflected in population structures. Finally we analyze the frequency of this polymorphism and the incidence of shovel-shaped teeth to discuss the evolutionary mechanisms of indigenous peoples of America.