Combined genetic deficiencies of the classical complement pathway are strongly associated with both systemic lupus erythematosus and primary Sjögren's syndrome
ObjectiveComplete genetic deficiency of the complement component C2 is a strong risk factor for monogenic systemic lupus erythematosus (SLE), but whether heterozygous C2 deficiency adds to the risk of SLE or primary Sjögren's syndrome (pSS) has not been studied systematically. Here we investigated heterozygous C2 deficiency and C4 copy number variation in relation to clinical manifestations in SLE
