Around the same time, as part of an evaluation for keratoconjunctivitis sicca, along with nonnephrotic-range proteinuria, the proband was diagnosed with SLE and Sjogren syndrome based on positive antineutrophil antibody, antidouble-stranded DNA, Sjögren's syndrome antigens A (anti-SSA), Sjögren's syndrome antigens B (anti-SSB) testing, and low C4. This evidence concerns the gene C4A and systemic lupus erythematosus.