A new familial heredodegenerative disorder with pancytopenia, immunologic deficiency, and cutaneous malignancies is reported. One patient had a prolonged course of multiple pneumothoraces, infections, and cutaneous malignancies. His immunologic abnormalities included near absence of IgA, elevated IgG with later development of abnormal γ-globulin, and defective delayed hypersensitivity. At autopsy at age 23, no thymus gland was found. He also had secondary amyloidosis, possibly resulting from bilateral osteomyelitis of both legs due to Serratia which had become generalized at death. His younger brother had severe pancytopenia responsive to methyltestosterone therapy. The differential diagnosis of this disorder included Fanconi's anemia, dyskeratosis congenita, ataxia-telangiectasia, and the other similar known heredodegenerative disorders, but most likely represents a new disorder with similarities to all heredodegenerative disorders and to some other genetic immunologic disorders.