Familial chilblain lupus (FCL)

Familial chilblain lupus (FCL) is a rare, inherited form of cutaneous lupus with prominent skin manifestations in acral parts of the body. Two families with autosomal dominant-inherited chilblain lupus have been reported. First symptoms manifest in early childhood, developing hypergammaglobulinemia and rheumatoid factor antibody production. In FCL, missense mutations in TREX1 that decrease its exonuclease activity were described. The failure of DNA degradation can result in aberrant immune response.