Molecular characterization of the complement C1q, C2 and C4 genes in Brazilian patients with juvenile systemic lupus erythematosus.

Objective: To perform a molecular characterization of the C1q, C2 and C4 genes in patients with juvenile systemic lupus erythematosus.

Methods: Patient 1 (P1) had undetectable C1q, patient 2 (P2) and patient 3 (P3) had decreased C2 and patient 4 (P4) had decreased C4 levels. All exons and non-coding regions of the C1q and C2 genes were sequenced.