C1q polymorphisms are associated with SLE, serum C1q and CH50 levels in a stable founder population of patients with SLE. Although the studied population was small and allele frequencies were low, this is the first study to suggest an association of C1q polymorphisms with SLE.

RAGE polymorphisms are associated with susceptibility to SLE and LN. In addition, some of these polymorphisms are likely to be associated with disease severity and initial response to treatment in LN.