Serum zinc levels in heterozygous carriers of the gene for acrodermatitis enteropathica: identification of a carrier state is not possible.

Three cases of acrodermatitis enteropathica (a.e.) from two nonrelated families are described. Two siblings had characteristic symptoms of a.e. in childhood. Both survived to adulthood without treatment, at which time the clinical picture became uncharacteristic of a.e. Even so, the serum zinc levels confirmed the diagnosis in both cases. The third case showed classic symptoms of a.e.; the patient had a greatly reduced serum zinc level and responded at once to treatment with zinc sulphate. Heterozygous carriers of the gene for a.e. have often had slightly reduced serum zinc levels. The value of this test could probably be improved by correcting the normal range of serum zinc for factors known to influence this, such as the patient's age and serum albumin level. The normal range ought also to be corrected for diurnal and postprandial variations of serum zinc.