Protease inhibitors in sera as possible indicators of familial hypothyroidism.

Both synthesis and degradation of proteins are reduced in the hypothyroid state. The possible involvement of serum trypsin and chymotrypsin inhibitors has been studied in a family that, for four successive generations, had clinical or subclinical hypothyroidism. Increased trypsin- and chymotrypsin-inhibiting activity was demonstrated in the sera of the four clinically hypothyroid women. Cellulose acetate electrophoresis of the sera of these patients and of two other subclinical hypothyroid family members disclosed the distinct appearance of an additional fraction in the alpha 2-globulin zone. The serum protein electrophoretic pattern changes observed in familial hypothyroidism might be genetically determined. Such changes could precede the clinical onset of the disease, thus serving as a possible indicator of the hypothyroid state.