One hundred nineteen Waiãpi Indians and 348 inhabitants of Manaus, Amazonas, were tested using nine enzyme genetic systems in the first population and two in the second. The Waiãpi showed some marked differences compared to South American Indian averages in ACP*A (1% vs. 14 ± 9%), GLO1*1 (9% vs. 30 ± 14%) and ESD*1 (99.6% vs. 70 ± 17%), while ESD*1 and CA2*1 prevalences in the Manaus population were within the range previously found in the northern region of Brazil (ESD*1: 85% vs. 80-94%; CA2*1: 98% vs. 89-99.8%). The almost identical frequencies obtained for these two markers in this population, when the sample was subdivided according to skin color, suggest that such morphological classifications have little value in this region. Genetic distances between the Waiãpi and other tribes, obtained using these and other genetic markers, showed good parallelism with the geographical distances which separate these Indians from the other groups considered.
