No abstract

Two hundred and one unrelated French Basque individuals were studied for HLA-A, B, C, DR and Bf polymorphisms. The results show that the Bf S0.7 (Bf S1) variant, which is known to be associated with HLA-Bw21, presents a highly significant linkage disequilibrium with a subtypic specificity, i.e., Bw50 (delta = 0.0123, delta S=100%, P less than 10(-8)). As neither Bf S0.7 variant nor Bw50 antigen is found in Mongoloid populations, it is suggested that in evolutionary terms, the Bf S0.7 mutation is a more recent event than the HLA-Bw21 split.

Summary We studied 201 unrelated French Basque individuals for HLA and Bf polymorphisms. The haplotypes of eighty‐seven of them were deduced from family studies. The results show the frequency of the Bf F1 allele (0.1393) which is the highest one currently reported. They confirm the high frequencies of HLA‐Aw19.2 and B18 previously reported in that population and show that a whole haplotype with strong linkage disequilibria, namely Aw19.2, Cw5, B18, Bf F1, DRw3 is frequent. On the other hand, the gene frequency of Bf S is decreased (0.5497) as compared with the other European Caucasoïd populations, while a slight increase in the Bf F gene frequency (0.2960) appears. These results point out that it is of importance to consider the genetic background in choosing the population where linkage disequilibria are to be studied.

Fourteen HLA‐A and 18 HLA‐B antigens were studied in three samples of Pyrenean populations: 198 unrelated individuals of a “Pays Basque” group; 212 non‐Basque individuals from a valley in Beam, l'Ouzom; and 73 non‐Basque individuals from the neighboring valley of Bareges. The results in the Basque and the non‐Basque people from l'Ouzom were comparable: the gene frequencies of HLA‐A29, Aw19.2, B17 were increased and the haplotypes HLA ‐ Aw 19.2, B18; A29, B12; A2, B5; Al, B17 were found frequently with a striking linkage disequilibrium; HLA‐B18 had an increased gene frequency in all these Pyrenean populations, while Bw35 was frequent in l'Ouzom and Bareges, but not among the Basques. The characteristics of Bareges were very different: the gene frequencies of HLA‐A2, All, B7 were increased while the frequency of HLA‐B5 was low; the most characteristic haplotypes were HLA‐A2, B12; A2, B18; All, Bw35; All, B27. It is interesting to note discrepancies between ethnic and HLA classification of the Basques and the non‐Basque population of l'Ouzom. The HLA characteristics are quite different in the Bareges sample, more closely resembling those of Northern Europe.

We report the study of a serum from a polytransfused patient, that contains an anti-HL-A8 antibody reacting by the platelet complement fixation microtechnique. The specificity is confirmed by a study on a panel of 112 different platelets and by experiments of absorption-elution on platelets, lymphocytes and granulocytes.

The analysis of 182 selected anti‐B cell sera on 102 cells allowed us to identifysseveral clusters of sera. They showed no correlation with HLA‐A, B or C specificities but many associations with the HLA‐D determinants. In 10 families, most of these sera segregated with HLA, and five recombinants showed a linkage with the BD or D end part of the MHC. The panel distribution and the family analysis indicated that at least one (the Ly‐Li system) and probably two segregant series could exist close to the HLA‐D locus.