A sample of 121 Piaroa Indians from the Federal Amazonia Territory (Ve
nezuela) was studied for the following serum protein polymorphisms: ha
ptoglobin (HP), group-specific component subtypes (GC), orosomucoid (O
RM), third component of complement (C3), transferrin C subtypes (TF) a
nd alpha1-antitrypsin subtypes (PI). The gene frequencies in the whole
sample were: HP1 = 0.821; GC1S = 0.698; GC1F = 0.058; GC2 = 0.244; OR
M(S) = 0.434; C3S = 0.699; C3F = 0.289; C3var = 0.012; TF(C1) = 0.955;
PI(M1) = 0.467; PI(M2) = 0.004; PI(M3) = 0.529. The studied Piaroa sa
mple came from three different communities: Gavilan, Paria and Alto Ca
rinagua. The distribution of GC, C3 and HP polymorphisms was heterogen
ous within the three groups. All the examined serum protein markers we
re polymorphic, in contrast to some enzymatic markers (ADA, DIA, 6PGD,
AK) previously studied, which were shown to be monomorphic in the Pia
roa. The results were compared with data from other populations living
in the same territory.