Linked loci in chromosome 1 (FXIIIB, HF, PEPC) and their variability in Brazilian Indians

A total of 352 individuals living in seven localities of two Brazilian Indian groups (Macushi and Içana River Indians) were variously studied for coagulation factor XIIIB, human factor H, and a new polymorphism of peptidase C. No significant inter- or intra-tribal differences were found for the FXIIIB alleles, the frequencies varying around 95% for F13B*3 and 5% for F13B*1. Results for HF were heterogeneous, HF*A presenting a much higher frequency among the Macushi (32%) than among the Içana River Indians (9%). Intratribal differences were also found among both groups. Linkage disequilibrium exists between alleles of these two systems (0.03 ± 0.01). These are the first results for human factor H obtained among Amerindians. The data for PEPC were limited to the Içana River Indians. There is heterogeneity among the three localities sampled and evidence of moderate linkage disequilibrium between markers in this locus and in F13B (0.02 ± 0.01). © 1992 Wiley-Liss, Inc.