Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.2.1.22 (cystathionine beta-synthase)
 965 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although the major biochemical abnormality due to methylenetetrahydrofolate reductase (MTHFR) deficiency is hyperhomocyst(e)inemia, its pathogenicity appears to involve more than homocysteine toxicity. In patients with severe MTHFR deficiency, a metabolite(s) other than hyperhomocyst(e)inemia also appears to be associated with its clinical manifestation in cerebrovascular disease. To elucidate the specific role of the TT genotype of MTHFR in the development of cerebral infarction with and without cognitive impairment, we determined the prevalence of hyperhomocyst(e)inemia and the C677T genotypes of MTHFR in 143 patients with vascular dementia, 122 patients with cerebral infarction, and 217 healthy subjects matched for age and sex. Prevalence of hyperhomocyst(e)inemia [homocyst(e)ine >/=15 micromol/L] was higher in cerebrovascular patients with or without dementia than in normal control subjects (42.6%, 20.5%, and 10.1%, respectively; P=0.001). In contrast, a higher frequency of MTHFR TT genotype was found only in demented patients compared with nondemented patients and healthy controls (25.2%, 9.8%, and 12.0%, respectively; P=0.01). When the study subjects were divided into normohomocyst(e)inemic and hyperhomocyst(e)inemic groups, the TT genotype was significantly associated with the risk for vascular dementia in the hyperhomocyst(e)inemic group (odds ratio 4.13, 95% CI 2.18 to 7.85; P=0.03) but not in the normohomocyst(e)inemic group. Demented patients with multiple infarcts had a higher frequency of TT genotype (odds ratio 3.13, 95% CI 2.23 to 4.39; P=0.0007), whereas those with a single infarct did not (odds ratio 2.03, P=0.15). In contrast, there was no significant association of the TT genotype with multiple infarcts in hyperhomocyst(e)inemic stroke patients. Taken together, these findings indicate a possible role of MTHFR TT genotype combined with hyperhomocyst(e)inemia in the pathogenesis of vascular dementia. Similar to the relationship between homocystinuria due to severe MTHFR deficiency and severe cystathionine beta-synthase deficiency, the TT genotype of MTHFR in hyperhomocyst(e)inemic subjects is differentiated from the cases of the TT genotype without hyperhomocyst(e)inemia or hyperhomocyst(e)inemia without the TT genotype in the development of cerebrovascular disease.
 ...
PMID:Pathogenicity of thermolabile methylenetetrahydrofolate reductase for vascular dementia. 1093 12

Homocystinuria is a congenital metabolic disorder, and has been known as life-threatening risk factor of vascular disease including ischemic stroke. We report a case of cerebral infarction due to homocystinuria. The patient was a 21-year-old woman exhibiting left hemiparesis and a previous history of ectopia lentis. Magnetic resonance imaging showed multiple fresh infarctions in the right frontal and temporal lobes, basal ganglia, corona radiata, and internal capsule. The right common carotid angiogram demonstrated complete occlusion at the origin of the right internal carotid artery. Further investigation clarified increased level of serum methionine and homocysteine and urinary homocystin due to cystathionine beta-synthase deficiency. Homocystinuria was diagnosed as the cause of cerebral infarction. The patient was treated by low methionine diet and administration of folic acid, cobalamin, and aspirin. It should be recognized that some patients with homocystinuria are missed in the neonatal screening for congenital metabolic disorders. Recent studies indicated that the homocysteinemia is one of risk factors of ischemic stroke in the general population as well as in the patients of homocystinuria. We recommend metabolic screening for homocystinuria, when treating a juvenile patient with ischemic stroke of unknown etiology.
 ...
PMID:[A case of young adult presenting with cerebral infarction caused by homocystinuria]. 1555 67