Other Names: acquired partial lipodystrophy, cephalothoracic lipodystrophy, and progressive lipodystrophy
Barraquer–Simons Syndrome is a rare form of lipodystrophy, which first affects the head, and then spreads to the thorax. The etiology of this condition is has not been fully clear. Lipodystrophy is often associated with glomerulonephritis, low C3 serum complement levels, and the presence of a C3 nephritic factor. C3 nephritic factor is a serum immunoglobulin G that interacts with the C3bBb alternative pathway convertase to activate C3. C3 nephritic factor induces the lysis of adipocytes that secrete adipsin, a product identical to complement factor D. The distribution of the lipoatrophy may be dictated by the amounts of adipsin secreted by the adipocytes at different locations.