The distribution of phenotypes controlled by two loci on chromosome 6 has been studied in a series of 239 patients with type 1 (insulin-dependent) and 297 patients with type 2 (non-insulin-dependent) diabetes mellitus. At the properdin factor B (Bf) locus there is a significant increase in the frequency of the Bfs1 and BfF1 alleles for type 1 patients, and the combined increase in frequency of Bfs1 and BfF1 in those patients is highly significant. The relative risk for F1 is 6.2 and for F1 and S1 combined is 5.3. These results confirm the association with F1 reported recently by Raum and co-workers in Boston. The two rare alleles Bfs1 and BfF1 are in significant negative disequilibrium with HLA B8.
For the glyoxalase (GLO) locus there is a slight but nonsignificant increase in the frequency of the GLO2 allele, but a significant disturbance in the distribution of the GLO phenotypes for type 2 patients. These results for the GLO alleles may be due to stratification in our series of type 2 patients. Further studies are in progress to test this hypothesis.