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

Early diagnosis and improved treatment are leading to the potential for increased reproductive capability in homocystinuria due to cystathionine beta-synthase (CbetaS) deficiency, but information about reproductive outcome and risk of thromboembolism in pregnancy is limited. To provide further information, clinical and biochemical information was obtained on women with maternal homocystinuria, on their pregnancies and on the offspring. This information included blood sulphur amino acids and total homocysteine, CbetaS gene mutations and developmental and cognitive scores in the offspring. The study involved 15 pregnancies in 11 women, of whom 5 were pyridoxine-nonresponsive and 6 were pyridoxine-responsive. Complications of pregnancy included pre-eclampsia at term in two pregnancies and superficial venous thrombosis of the leg in a third pregnancy. One pregnancy was terminated and two pregnancies resulted in first-trimester spontaneous abortions. The remaining 12 pregnancies produced live-born infants with normal or above-normal birth measurements. One offspring has multiple congenital anomalies that include colobomas of the iris and choroid, neural tube defect and undescended testes. He is also mentally retarded and autistic. A second offspring has Beckwith-Wiedemann syndrome. The remaining 10 offspring were normal at birth and have remained normal. There was no relationship between the severity of the biochemical abnormalities or the therapies during pregnancy to either the pregnancy complications or the offspring outcomes. The infrequent occurrences of pregnancy complications, offspring abnormalities and maternal thromboembolic events in this series suggest that pregnancy and outcome in maternal homocystinuria are usually normal. Nevertheless, a cautious approach would include careful monitoring of these pregnancies with attention to metabolic therapy and possibly anticoagulation.
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PMID:Reproductive fitness in maternal homocystinuria due to cystathionine beta-synthase deficiency. 1222 60

Homocysteine (Hcy) is a sulfur-containing amino acid produced when methionine is demethylated. The majority of Hcy undergoes transsulfuration to cysteine by cystathionine beta-synthase (CBS), of which vitamin B6 (pyridoxine) is an essential cofactor. The remainder of Hcy is remethylated by methionine synthase (MS), of which vitamin B12 (cobalamin) is an essential cofactor along with methylenetetrahydrofolate (MTHF). MTHF is generated by the enzyme MTHFR-reductase (MTHFR). High levels of Hcy can result from a variety of aquired factors (deficiency of vitamins B6, B12 and folic acid, high meat diet, smoking and others) or genetic (abnormalities of methionine--homocysteine metabolism). Hyperhomocysteinemia is associated with premature atherosclerosis and venous thromboembolism; so called "cholesterol of XXI. age". Results of many studies suggest that hyperhomocysteinemia, homozygous state for MTHFR gene mutation, folate deficiency are probably risk factors for recurrent fetal loss, intrauterine fetal death, thrombo-embolic disease in pregnancy, neural tube defects and congenital cardiac malformation at infants and other placental diseases (pre-eclampsia, placental abruption and intrauterine growth restriction IUGR). Those irregularities are very interesting and important for obstetricians and gynecologists. The plasma homocysteine values can be modulated by vitamins, vitamin B6 and folic acid in particular. The potential for research and possible prevention in this area is immense.
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PMID:[Hyperhomocysteinemia and pregnancy complications]. 1518 72

In its biological complexity, pregnancy represents a challenge both for the maternal organism and the fetal development and growth. During this period, some peculiar pathologies of pregnancy can occur which can involve or the fetus only i.e.: spontaneous pregnancy loss, intrauterine growth retardation, defects of neural tube, until the intrauterine fetal death; or pathologies occurring in the placenta and thus involving maternal organism and fetus too, such as pre-eclampsia. All these pathologies recognize many risk factors, among them the hyperhomocysteinemia. Hyperhomocysteinoemia can be caused by enzymatic defects or lack of some vitamins cofactors (vitamin B6, vitamin B12 and folic acid). The genetic defects which, as homozygous genotype, cause high plasma levels of homocysteine are already well known; they lead to an activity reduction of the enzymes responsible for their metabolism, for example: the deficiency of cystathionine beta-synthase; the deficiency of the methylcobalamine production; the deficit of the 5-10 methylenetethrahydrofolate reductase (MTHFR). However, even the heterozygous genotypes, which have a variable incidence from 1/70 to 1/200 and directly of 5-15% for the C677T mutation of the 5-10 MTHFR, can determine a mild hyperhomocysteinemia with a consequent cardiovascular risk. The close implications, widely demonstrated in the international literature, between hyperhomocysteinemia and the maternal-fetal diseases are described.
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PMID:[Hyperhomocysteinemia: associated obstetric diabetes and fetal malformations]. 1630 66