Several hereditary syndromes linked to renal cancer are characterized by mutations in genes coding for key metabolic enzymes, such as fumarate hydratase (FH) and succinate dehydrogenase B (SDHB), and defects in these enzymes associate with malignancy and poor prognosis in renal cell carcinoma (RCC)8,9. The gene discussed is FH; the disease is renal carcinoma.