[Systemic lupus erythematosus in hereditary complement 4 deficiency].

A genetically determined complete absence of the fourth component of complement, C4, associated with systemic lupus erythematosus has been detected in one member of another family. Observations made in this patient, the ninth described so far in whom systemic lupus erythematosus and C4 deficiency occur have confirmed that this condition presents with a characteristic clinical picture: there is pronounced sensitivity to sunlight and to cold with Raynaud's phenomenon; skin lesions are found predominantly in locations typical for subacute cutaneous lupus erythematosus and, remarkably, on the palms and soles. As was the case in two families described earlier, the C4-deficient gene was associated with the HLA-haplotype AW30, B18, DR7; BfS1.