Familial clustering of systemic lupus erythematosus in the cayman islands.

Abstract

To describe the unusual clustering of systemic lupus erythematosus (SLE) in a family from the Cayman Islands. An observational retrospective study of SLE was done following an index case of mixed connective tissue disease in a 51-year old West Indian woman of African descent. Her two daughters of the same father, who is of Cayman Islands origin, were also diagnosed with SLE. A family tree was subsequently drawn up to 1890 to identify other cases in the same family. There were 13 cases identified and all occurred between the 6th and the 8th generation. A family tree linked all cases to a man from the Cayman Islands who died in 1890. The nine cases with full medical records showed eight females and one male (8:1). The mean age at diagnosis was 29 years; polyarthritis occured in all nine patients (100%), kidney involvement in 6/9 (66.6%), skin rash in 6/9 (66.6%), pleuritis and pericarditis in 6/9 (66.6%) and anaemia in 6/9 (66.6%). The autoantibodies were mainly ANA in all patients (100%) and anti-dsDNA in 8/9 (88.8%). The unusual extensive familial clustering in this study represents the first to be described in a West Indian population where SLE is most prevalent and may suggest a genetic predisposition.