TNFRSF10A and type 1 diabetes mellitus: For example, HLA genotyping in African American patients found that the African-specific DR9 (DRB1*09:01-DQA1*03:01-DQB1*02:01g) haplotype in combination with DR4 mimics risk for T1D seen in patients with DR3/DR4 heterozygosity in European populations.