Variability of the BCHE gene in Amerindians from Paraná, Brazil.

Objective: This study aims to better understand the variability of the BCHE gene, and regions adjacent to it, in different populations. More specifically, it also aims to analyze the diversity of this DNA segment among two Amerindian populations, whose distinct characteristics provide us an extremely interesting material for genetic, evolutionary and anthropological studies, since they diverge genetically and culturally in spite of a very close living relationship in space and time.

Methods: The two Amerindian populations analysed were from Guarani-Mbyá and Kaingang ethnic groups, both from the Rio das Cobras indian reservation area (Paraná, Brazil). The other populations data were obtained from the HapMap Project data, NCBI data and previously studies. The variability of seven SNPs was analyzed: two downstream, three within and two upstream of the BCHE gene.

Results: The number of different BCHE variants in Amerindians is lower than in other populations. The present data are in accordance with the genetic distance between Guarani and Kaingang, and from them to other populations. Some SNPs (rs3495, rs7624915 and rs4387996) presented an interesting frequency pattern, with a higher frequency of the ancestral allele in the region of the modern human origin and its frequency decreasing gradually, from Africa toward the Americas.

Conclusions: Despite the geographical coexistence throughout their dispersion, each of these two Amerindian groups retains a high degree of genetic identity, probably maintained by cultural and social isolation.