GAD1 and type 1 diabetes mellitus: Many familial cases of anti-GAD65 neurological syndromes, such as limbic encephalitis, ataxia, and stiff person syndrome, were reported, suggesting a genetic predisposition.109, 110, 111, 112Anti-GAD was linked toDQA1*05:01–DQB1*02:01–DRB1*03:01, andDQA1*03:01–DQB1*03:02–DRB1*04:01, with the latter also being associated with T1DM.101, 113Conversely, a recent GWAS with 167 patients identified 16 loci associated with anti-GAD, highlighting significant loci in the HLA class-I region and numerous genes involved in innate and adaptive immunity.101