Progressive systemic sclerosis in a family: case report of a mother and son and review of the literature.

Progressive systemic sclerosis (PSS) developed in a 6-year-old boy and in his 38-year-old mother 9 years later. Both parent and child had Raynaud's phenomenon, integumental sclerosis, and pulmonary involvement, but they differed in other aspects of their disease. Previous descriptions of the familial occurrence of PSS are reviewed and compared to the present case reports. Environmental and genetic factors of possible etiologic significance are discussed.