High heterogeneity of Apolipoprotein E gene frequencies in South American Indians

The apolipoprotein E (APOE) polymorphism was investigated in 186 individual s from six South American Indian tribes, and the results integrated with th ose previously presented for this ethnic group. The three APOE alleles comm only reported in other populations were also observed in South Amerindians with a highly heterogeneous distribution. As in other populations, APOE*3 w as the most common allele (51-98%) followed by APOE*4 (2-47%). These two is oforms were identified in all tribes, but APOE*2 was observed among the Wai Wai (2%) and Mataco (4%) only. No previous indications of inter-ethnic adm ixture were observed among the Wai Wai, but the introduction of this allele among the Mataco through non-Indian sources cannot be excluded.