PROTOCOL OUTLINE:
Participants undergo qualitative genetic analysis of complement-related proteins. Studies include: genomic re-arrangement of 4-gene unit, C4 DNA sequence and RNA expression, type-1 complement receptor DNA sequence, Fc-gamma receptor IIIA isoform analysis, classical and alternative complement activation pathway assays, plasma C4 and C4d protein levels, and immunoglobulin patterns in glomerular deposits.