Brief Genetics Report A 212-kb Region on Chromosome 6q25 Containing the TAB2 Gene Is Associated With Susceptibility to Type 1 Diabetes

The IDDM5 gene, which is identified by whole-genome searches, is located on chromosome 6q25. TAB2 (MAP3K7IP2 [mitogen-activating protein kinase kinase kinase 7 interacting protein 2]) is a potential candidate gene for type 1 diabetes because it is located on chromosome 6q25 and is involved in nuclear factor (NF)B regulation. We have conducted familial association studies using 478 families and demonstrate that a type 1 diabetes susceptibility gene resides within a 212-kb region containing the TAB2 gene (Tsp 1.0 10 2 to 4.0 10 ). No amino acid polymorphisms were detected in TAB2; however, multiple single nucleotide polymorphisms (SNPs) found within 5 untranslated, 3 untranslated, and intron regions were associated with type 1 diabetes susceptibility. Two additional genes, LOC340152, a predicted gene with currently unknown function, and SMT3, which has homology to SUMO (small ubiquitin-related modifier) were found within the 212-kb region and were associated with type 1 diabetes susceptibility. Functional studies of the three genes will be required to determine their biological relevance to type 1 diabetes. However, both TAB2 and SUMO are involved in NFB activation and may thus be involved in type 1 diabetes through apoptosis in pancreatic -cells. Diabetes 53:1890–1893, 2004