The IDDM 17 locus was mapped to an 8-cM interval at chromosome 10q25.1 based on linkage in a large Bedouin Arab family with 19 affected relatives. Caspase 7 (CASP7), an apoptosis-related cysteine protease, is one of the few known genes in this region. CASP7 is involved in the activation cascade of caspases responsible for apoptosis execution. Only 1 of the 18 SNPs in CASP7 (SNP144692) differed significantly in frequency in the haplotypes found in affected individuals compared to control Bedouin haplotypes. This same SNP showed evidence of association with diabetes in a subset of patients (DR3/DR4*0302) from HBDI families.