C-4 AND FACTOR-B POLYMORPHISMS IN TYPE-1 (INSULIN-DEPENDENT) DIABETES

  • 1 June 1988
    • journal article
    • research article
    • Vol. 36  (6) , 791-794
Abstract
The haplotypic frequencies of the fourth component of complement (C4) and factor B (Bf) have been determined in 44 Alsatian type 1 diabetics. An increased frequency of the rare allele Bf F1 (9.1% vs 1.5%) and of the silent alleles of C4 (C4 AQO:21.6% vers 15.5%-CA B QO:29.6% vs 16.0%) was observed in diabetics in comparison to the general population of the same geographic area. A complete HLA haplotype determination has been obtained in 24 type 1 French diabetics. Three haplotypes were associated with the diabetic susceptibility:HLA-A30 CW5 B18 BfF1 C4A3BQO DR3 (18.75% vs 0.86%), HLA-A1 CW7 B8 BfS C4AQOB1 DR3 (15.58% vs 4.17%), HLA-A2 CW3 BW62 BfS C4A3B3 DR4 (6.25% vs. 0.45%). The authors suggest that the silent alleles of C4 could modulate the expression of the diabetic susceptibility genes by lowering of the serum C4 hemolytic activity.