We determined the molecular basis of cystathionine beta-synthase (CBS) deficiency in three siblings with pyridoxine responsive homocystinuria using a significantly improved mutation screening method in bacteria. The phenotypic expression of the siblings differed even though their CBS genotypes were identical. The paternal allele contained a linked pair of mutations, C233G and G306C, correspondi...

Osteoporosis occurs commonly in homocystinuria. The underlying pathobiochemical mechanism remains unclear: disturbed cross-lin­ king of collagen has been suggested but this hypothesis has not been fully tested, nor have studies on collagen synthesis been performed. We therefore used recently available noninvasive tests for collagen synthesis and cross-linking to examine 10 patients with homocys...

The clinical picture of classical homocystinuria is diverse. This is the first report of an adult homocystinuric patient with non-traumatic spontaneous small bowel perforation. A 47-year old man presented with abdominal rebound tenderness, hypotension and tachycardia, anemia, and elevated markers of inflammation. Other routine laboratory tests were normal. Abdominal x-ray showed no free air. An...

Homocysteine is a chemical in the blood that is produced when an amino acid (a building block of protein) called methionine is broken down in the body. We all have some homocysteine in our blood. Elevated homocysteine levels (also called hyperhomocysteinemia) may cause irritation of the blood vessels. Elevated levels of homocysteine show an increased risk for (1) hardening of the arteries (athe...

A 24 day old girl with homocystinuria and hypomethioninaemia caused by methylenetetrahydrofolate reductase deficiency presented with rapidly progressing encephalopathy and myopathy. An almost complete recovery was achieved by treatment with betaine.

Homocystinuria, a condition associated with decreased hepatic cystathionine synthetase activity (Mudd, Finkelstein, Irreverre, and Laster, 1964), is characterized by increased urinary homocystine and methionine, by increased serum methionine levels, and by low cystathionine levels in brain (Gerritsen and Waisman, 1964b). It is not known how these biochemical findings are related to the multiple...