[Familial sarcoidosis. Apropos of 22 families]

Twenty-two families, the ethnic origins of which were Caucasian (16) or mixed Caribbean (6), each with two or three members suffering from sarcoidosis, were studied. The frequency of familial sarcoidosis when all races are considered is 2.4 p. 100 but it is higher in people born in the Caribbean. Clinically, this form is no different from non-familial cases but there is a tendency, especially in homozygotic twins, for the dates of revelation of the disease to be very close to each other, and for the clinical and radiological features and the evolution to be the same. A higher frequency of pairs of the same sex with equal numbers of parent-sibling and sibling-sibling pairs were observed. There was no predominance of mother-sibling with respect to father-sibling pairs. The HLA system study was too fragmented to draw any conclusion about the mode of transmission of familial sarcoidosis.