Bf polymorphism and its relationship with HLA antigens in a sample of the Spanish Population: high BfF1 frequencies.

Bf allele frequencies were studied in a sample of the normal Spanish population and in family haplotypes. BfF1 shows a frequency higher than in other Caucasoid populations and closer to that found in Negroids. Basques show an even higher BfF1 frequency BfF1 is in strong linkage disequilibrium with B18. HLA-Bw44 is found to be the B12 split in linkage disequilibrium with BfF and Bw50-BfS1 association is confirmed. DR3--BfF1 are not in linkage disequilibrium in the normal Spanish population, in contrast to DR3--BfF1 in linkage found in a diabetic Spanish population. Results are discussed on the bases of the paleo-North African Iberian population origins and of the use of Bf to define B12 and Bw21 splits.