Bf Polymorphism and its Relationship with HLA Antigens in a Sample of the Spanish Population: High BfF1 Frequencies

Abstract

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 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.

The Northern Migrations from a drying Sahara (6,000 years BP): cultural and genetic influence in Greeks, Iberians and other Mediterraneans

“…Several studies (Degos & Dausset 1974;Cambon-Mouzon et al 1982) and our own previous research (Rodríguez-Córdoba et al 1981;Arnaiz-Villena et al 1981;Regueiro & Arnaiz-Villena 1988) have pointed out that the HLA-A30-B18-DR3-BF*F,1 haplotype was a marker for Basques, Sardinians and Spaniards. Its frequency in other populations was significantly lower, except for Mediterranean North Africans; this suggested a paleo-North African/Iberian origin for part of the Basque gene pool (Arnaiz-Villena et al 1981).…”

“…Several studies (Degos & Dausset 1974;Cambon-Mouzon et al 1982) and our own previous research (Rodríguez-Córdoba et al 1981;Arnaiz-Villena et al 1981;Regueiro & Arnaiz-Villena 1988) have pointed out that the HLA-A30-B18-DR3-BF*F,1 haplotype was a marker for Basques, Sardinians and Spaniards. Its frequency in other populations was significantly lower, except for Mediterranean North Africans; this suggested a paleo-North African/Iberian origin for part of the Basque gene pool (Arnaiz-Villena et al 1981). Also, complete HLA data on Basques and Spaniards (Martínez-Laso et al 1995) have been analysed by DNA indirect sequencing and compared with data from North African populations (Algerians) with at least 70% Berber component (Julien 1951;Benmamar et al 1993;Rachid 1994;.…”

“…On the contrary, the suggested conformity of Iberian craniometric data to a demic diffusion model simply does not exist (Cavalli-Sforza 1976); Mesolithic and Neolithic bones show clear continuity (Jackes et al 1997b). Second, genetic data in North Africans, Spaniards, Basques, Portuguese and Cretans (Arnaiz-Villena et al 1981;1999b;Corte-Real et al 1996;Izaabel et al 1998) support substantial gene flow from paleo-North African populations to Iberia. Also, common extended HLA haplotypes between present day North African and Iberian populations, including Basques, exist (Arnaiz-Villena et al 1997;Izaabel et al 1998).…”

Major histocompatibility complex complement (MHC) Bf alleles show trans species evolution between man and chimpanzee

“…Bf*F1 is also important in severe SLE 6 , whether these associations are primary or not is not clear, but HLA-DRB1*03:01 was quickly blamed, which is in linkage disequilibrium with Bf*F1 4 , 5 , 7 .C4 alleles may also be useful to study autoimmunity association 22 , 23 . In summary, Bf*F1 could be associated to autoimmune disease either by itself or together with HLA extended haplotypes containing HLA-DRB1*03:01 and Bf*F1.…”

“…C3 Convertase on alternative pathway is composed of C3b and Factor B (Bb fragment) proteins 2 . Several diseases have been linked to some allelic Factor B (Bf) polymorphism extant in Ba fragment 3 – 7 . Once C3b bounds to cell microbial or other surface, it can bind Bf protein, which is cleaved by Factor D to Ba and Bb fragments 1 , establishing BbC3b convertase on human pathogens surface.…”