Gene and Haplotype Frequencies of the Fourth Component of Complement (C4) in Type 1 Diabetics and Normal Controls

Abstract

C4 gene and haplotype frequencies were calculated from phenotype data of 380 unrelated Caucasian patients with insulin dependent (type 1) diabetes mellitus and were compared with analogous frequencies of 382 unrelated healthy Caucasian individuals. In diabetics, a significantly increased frequency of the rare allele C4B*3 (p<10- 7) and of the silent alleles C4A*QO (p<10- 7) and B*QO (p<0.002) was observed. Accordingly, insulin dependent diabetes is associated with partial C4 deficiency, which may contribute to the pathogenesis of the disease. We thank Dr. W. LUBOLDT (Blood Transfusion Service, University of Essen), who provided us with the sera of the control population.