Familial Fanconi syndrome with malabsorption and galactose intolerance, normal kinase and transferase activity. A report on two siblings.

Two siblings of Turkish-Assyrian extraction, whose parents were first cousins, had poor appetite, slow weight gain and retarded psychomotor development. When given milk the galactose concentration in blood increased. An oral galactose load showed a markedly reduced capacity to metabolize galactose. Fanconi syndrome was present as in classical galactosemia. A galactose-free diet reduced the aminoaciduria but did not normalize the renal tubular function nor the children's general condition. Galactokinase and galactose-1-phosphate uridyltransferase activities in red blood cells were normal. The physical appearance of the children (sparse subcutaneous fat, thin extremities and distended abdomen) and the results of vitamin A and xylose absorption tests, were in accordance with a malabsorption condition. Glucose, however, seemed to be absorbed normally from the gut. There was no evidence of primary liver disease. Since the condition did not normalize with a galactose-free diet, an enzyme defect of galactose metabolism is unlikely. Instead, a more general transport defect with autosomal recessive inheritance is proposed.