This study demonstrates that susceptibility to HS also has a genetic origin: on one hand, the presence of DRB1*01 or DRB1*11 makes disease onset easier; on the other hand, DRB1*07 could induce some resistance to the disease.
Human leukocyte antigen (HLA) typing in the patient disclosed the DRB1*11 allele, which has been reported to be associated with HSP, but the brother proved negative, suggesting that this allele was irrelevant to the HSP pathogenesis.