Background: Neonatal lupus erythematosus (NLE) is a syndrome characterized by dermatitis and congenital heart block. The disease is mostly associated with transplacental passage of maternal anti-Ro(SS-A) or anti-La(SS-B) antibodies. Maternal HLA-DR3 and DQ2 alleles are associated with NLE in white and North American black populations.

Objective: We sought evidence of a potential genetic disposition to NLE in mothers with a relatively homogeneous ethnic background.

Methods: Class II human major histocompatibility complex HLA-DRB1, DQA1, DQB1, and DPB1 alleles were determined by polymerase chain reaction–restriction fragment length polymorphism in anti-Ro(SS-A)–positive mothers as well as in infants from seven Japanese families with siblings concordant or discordant for disease expression of NLE.

Results: All seven mothers had two or three DQ alleles of DQA1 and DQB1 possessing specific amino acid residues, which are reportedly associated with anti-Ro(SS-A) autoantibody response in white and black populations. There was no class II HLA profile that distinguished disease manifestations of NLE in infants.

Conclusion: The HLA class II allele associations with anti-Ro(SS-A) autoantibodies that have been noted in other ethnic groups were also found in Japanese anti-Ro(SS-A)–positive mothers whose infants had NLE, suggesting shared susceptibility factors across racial barriers in maternal predisposition to Ro(SS-A) autoimmune response.

(J Am Acad Dermatol 1997;36:186-90.)