Uncultured human leukocytes contain no detectable cystathionine synthase activity. A method is described in which the addition of phytohemagglutinin (PHA) to short-term lymphocyte cultures results in a significant induction of enzymatic activity. This PHA-stimulated activity has characteristics that resemble those previously described for cystathionine synthase of normal liver and cultured fibr...

Gaull G E, Rassin D K, Struman J A. Letter: Pyridoxine dependency in homocystinuria. Lancet 1968; ii: 1302. 2 Reid D W J, Campbell D J, Yakymyshyn I Y. Quantitative amino acids in amniotic fluid and maternal plasma in early and late pregnancy. AmJ Obstet Gynecol 1971; 111: 251-8. 3 Mabry C C, Denniston J C, Coldwell J F. Mental retardation in children of phenylketonuric mothers. N EnglJ Med 196...

Inherited metabolic disorders are often characterized by the lack of an essential enzyme and are currently treated by dietary restriction and other strategies to replace the substrates or products of the missing enzyme. Patients with homocystinuria lack the enzyme cystathionine β-synthase (CBS), and many of these individuals do not respond to current treatment protocols. In this issue of the JC...

Inherited homocystinuria is a rare autosomal recessive aminoacidopathy which through early diagnosis can prevent its severe neurologic and vascular complications. Here we report a 9-year-old girl with homocystinuria, presenting with sequential symptoms of bilateral lens dislocation, skeletal complication, and eventually dystonia from the age of 4 years. Laboratory evaluation revealed severe hig...

Homocystinuria was diagnosed in 15 (0.59%) cases on screening 2560 children for aminoacidopathies. The commonest presenting features were ectopia lentis (95%) and mental retardation (86%). Other features included, dental anomalies (40%), osteoporosis (40%), behavioral problems (33%) and arachnodactyly (13%). Diagnosis was confirmed by iodoplatinate staining of one dimensional paper chromatograp...

Homocystinuria is the result of an inborn error in the metabolism of the essential sulphur-containing amino acid, methionine (Carson and Neill, 1962; Gerritsen, Vaughn, and Waisman, 1962). There is now good evidence (Mudd et al., 1964) to show that the basic defect in this disorder is an inactivity of hepatic cystathionine synthetase, which prevents the formation of cystathionine from homocyste...

A newborn mass-screening program for the early detection of phenylketonuria, maple syrup urine disease, homocystinuria, galactosemia, congenital hypothyroidism, congenital adrenal hyperplasia, using filter paper blood specimens, was started throughout Japan in 1977. The total number of newborns screened by March 2000 reached 29,657,738; this represents 95% of the newborns during this period. A ...