G6PD variants in three South American ethnic groups: population distribution and description of two new mutations.

A review is made of G6PD population surveys conducted in 4,558 European-derived, 2,484 admixed Black/Indian/White or Black/White, and 10,298 Indian subjects living in South America. Despite the fact that twice more Amerindians than Whites had been examined, no autochtonous variant was found among them, while seven different types (besides the most common Gd*B, Gd*A, Gd*A- and Gd*Med) were observed among the Whites. We also describe two new mutations in the G6PD molecule (Farroupilha, 977 C-->A and Lages, 40 G-->A), bringing the number of mutants characterized to 98. G6PD Lages is the most 5' mutation detected thus far. G6PD Seattle, previously found in the United States and Italy, seems to occur in other European countries and was observed by us in five independent Brazilian families.