Hereditary hemochromatosis and red cell aplasia.

A 63-year-old white man with myasthenia gravis and red cell aplasia was found to have hepatic iron overload. The differential diagnosis included hereditary hemochromatosis and secondary iron overload related to red cell aplasia. Family studies of siblings, including HLA typing, initially suggested a diagnosis of secondary iron overload. The investigation of a remote sibling led to the final diagnosis of hereditary hemochromatosis. The case illustrates the importance of complete family investigations in the differentiation between hereditary hemochromatosis and secondary iron overload and the potential hazard of using HLA typing as an indirect genetic test for hereditary hemochromatosis.