Homocystinuria due to Cystathionine Synthetase Deficiency: The Mode of Inheritance

Abstract

Deficiency of cystathioninie synthetase activity results in the clinical syndrome of homocystinuria. In both parents of a patient with homocystinuria, the hepatic cystathionine synthetase activity was 40 percent of that in unrelated control patients. These findings demonstrate that the metabolic error is inherited and suggest that the parents, although clinically normal, represent the heterozygous. state. A second case of homocystinuria also is shown to be associated with cystathionine synthetase deficiency.