ARCOIDOSIS is a multisystem disorder of unknown etiology, most commonly affecting young adults and presenting most frequently with bilateral bilar lymphadenopatby, pulmonary infiltration, and skin or eye lesions. The diagnosis is established most securely when clinico-radiographic findings are supported by histologic evidence of widespread noncaseating epitheloid cell granulomas in more than one organ or a positive Kveim-Siltzbach skin test. This skin test also reflects activity of the disease. Immunologic features are depression of delayed-type hypersensitivity, indicating T-cell anergy, and raised serum immunoglobulins, indicating B-cell overactivity. There may also be hypercalciuria with or without hypercalcemia. The course and prognosis correlate with the mode of onset; an acute onset with erythema nodosum usually heralds a self-limiting course with spontaneous resolution, while an insidious onset may be followed by relentless progressive fibrosis. Corticosteroids relieve symptoms and suppress inflammation and granuloma formation. ETIOLOGY The cause of sarcoidosis is unknown, so theories abound. Oranuloma formation is the final common pathway of several different and unrelated disorders. We do not know whether sarcoidosis is one disease resulting from one cause or whether it is a multicausal syndrome. Claims that it is an infection are longstanding and the most popular infective agents have been mycobacteria, fungi, and viruses. There has been speculation concerning a transmissible agent from human sarcoid tissue into foot pads of mice, but similar changes occur with control nonsarcoid lymph node tissue. 1 Even human foreskin fibroblast has been used for tissue culture of sarcoid lymph nodes but no viral cytopathic effect was observed. 2 The occasional occurrence of familial sarcoidosis suggests possible genetic influences. We have observed 16 families, among which 33 persons had sarcoidosis. The group comprised nine brother sister, four mother offspring, and one uncle-niece relationship, and it was also noted in husband and wife once. The clinical, radiographic, and other features of the disorder are similar in familial and sporadic sarcoidosis, but the course of one sister was considerably worse than that of her brother, suggesting adverse hormonal factors. Four of these families were from the West Indies, suggesting a racial predisposition to familial sarcoidosis. Turiaf has also noted a greater incidence in French West Indians from Marti