Pemphigus vulgaris in siblings: HLA-DR4 and HLA-DQw3 and susceptibility to pemphigus.

BACKGROUND: The association of pemphigus vulgaris with the HLA serotypes, DR4 and DRw6, and with the DQ-beta chain alleles, DQw1 and DQw3, suggests that there is a genetic predisposition to this disease. However, familial cases of pemphigus vulgaris are exceedingly rare.

OBJECTIVE: We studied two siblings with pemphigus vulgaris and three unaffected family members to determine whether an HLA allele was associated with the development of pemphigus vulgaris in this family.

METHODS: We utilized restriction fragment length polymorphism methods using the HLA-DR beta 1, HLA-DQ alpha, and HLA-DW beta 1 genes as cDNA probes.

RESULTS: We found that the affected siblings share the haplotype HLA-DR4 and the DQw.3.2 allele.

CONCLUSION: Our findings of gene sharing among siblings with pemphigus vulgaris lend support to previous studies of unrelated Caucasian patients, which implicated DQw3 allele polymorphisms in conferring susceptibility to pemphigus.