Fraternal concordance of types of abnormal hepatocellular mitochondria in Wilson's disease.

Three distinct patterns of structural abnormalities of mitochondria, indicated as types I, II and III and associated with steatosis, were identified in the hepatocytes of 40 of 42 asymptomatic and 8 of 22 symptomatic patients with documented Wilson's disease before treatment. No correlation was seen between the type of mitochondrial abnormality and the patient's age, hepatic copper concentration, degree of hepatic steatosis or serum aminotransferase level. However, comparison of the types of abnormal hepatocellular mitochondria displayed by five pairs and one trio of asymptomatic siblings revealed remarkably similar types of abnormalities in each family. The variety of mitochondrial types encountered in different families and the high degree of type identity in sibling relationships indicate that the structural changes are genetically determined.