Familial systemic lupus erythematosus in mother and son

Although the etiology of systemic lupus erythematosus (SLE) is thought to be multifactorial, genetic factors may play some role in its pathogenesis. Supportive of this hypothesis are the studies of identical twins and familial cases of SLE. We describe below a family in which mother and son both developed SLE. The mother was diagnoged as SLE at age 25, and had been treated with prednisolone. In February 1989, she had massive proteinuria. The onset of the son's disease was at age 13 in 1988, when he noted erythema and photosensitivity. At admission to our hospital in 1989, he had polyarthralgia, proteinuria, positive antinuclear antibody, positive anti-DNA antibody. Both two patients had a same haplotype, HLA A2.BW61(40).DR9. Two asymptomatic members of this family were also studied, the younger son had positive antinuclear antibody and hypocomplementemia.