HLA-DRB genotyping in Gilles de la Tourette patients and their parents

Gilles de la Tourette syndrome (GTS) is a common neuropsychiatric disorder of unknown cause. There is, however, growing evidence that both autoimmune and genetic factors are involved in the pathogenesis of GTS. In classical autoimmune disorders such as diabetes mellitus or multiple sclerosis, genetic susceptibility is at least in part conferred by human leucocyte antigen (HLA-) subtypes, in particular by distinct HLA-DRB alleles. We undertook modern, PCR-based HLA-DRB typing in 83 trios (affected index child and both parents) to investigate whether GTS may be associated with a particular HLA-DRB allele. The extended transmission/disequilibrium test (ETDT) was applied to analyze transmission disequilibrium for any of the 13 alleles detected. The ETDT failed to detect transmission disequilibrium for any allele at the DRB1 locus (overall allele-wise chi(2) (12) = 12.741, Monte Carlo P = 0.4998). Our results imply that the HLA-DRB locus does not confer genetic susceptibility to GTS.