homocystinuria
n. a genetic metabolic disorder characterized by a deficiency of an enzyme needed to convert L-homocystine to L-cystathionine. Intellectual disabilities often occur, along with a shuffling, ducklike gait and, in some instances, seizures or hemiplegia. Brain abnormalities are often due to arterial or venous thromboses. Also called cystathionine synthetase deficiency.