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[Biopterin and child neurologic disease].
No To Hattatsu. 2009 Jan; 41(1):5-10.NT

Abstract

Tetrahydrobiopterin (BH4) deficiencies are disorders affecting phenylalanine metabolism in the liver and neurotransmitter biosynthesis in the brain. BH4 is the essential cofactor in the enzymatic hydroxylation of 3 aromatic amino acids (phenylalanine, tyrosine, and tryptophan). BH4 is synthesized from guanosine triphosphate (GTP), catalyzed by GTP cyclohydrolase I (GTPCH), 6-pyruvoyl-tetrahydropterin synthase, and sepiapterin reductase (SR), and in aromatic amino acids, the hydoxylating system is regenerated by pterin-4a-carbinolamine dehydrolase and dihydropteridine reductase (DHPR). BH4 deficiency has been diagnosed in patients with hyperphenylalaninemia (HPA) by neonatal mass-screening based on BH4 oral-loading tests, analysis of urinary or serum pteridines, and measurement of DHPR activity in blood using a Guthrie card. BH4 deficiency without treatment causes combined symptoms of HPA and neurotransmitter (dopamine, norepinephrine, epinephrine, and serotonin) deficiency, such as red hair, psychomotor retardation, and progressive neurological deterioration. However, autosomal dominant GTPCH deficiency and autosomal recessive SR deficiency leads to BH4 and neurotransmitter deficiency without HPA and may not be detected by neonatal screening for phenylketonuria. The former is Segawa's disease, which is characterized by dopa-responsive dystonia with marked diurnal fluctuation and is caused by a defect of GTPCH, and the latter is SR deficiency, which is characterized by progressive psychomotor retardation, dystonia, and severe dopamine and serotonin deficiencies. Biochemical diagnosis is performed by the measurement of neopterin and biopterin levels, since both are low in Segawa disease, and the biopterin level is high in SR deficiency in cerebrospinal fluid. We must consider metabolic disorders of biopterin in child neurologic diseases with dystonia.

Authors+Show Affiliations

Department of Pediatrics, Osaka City University Graduate School of Medicine, Osaka. shintakuh@med.osaka-cu.ac.jp

Pub Type(s)

English Abstract
Journal Article
Review

Language

jpn

PubMed ID

19172809

Citation

Shintaku, Haruo. "[Biopterin and Child Neurologic Disease]." No to Hattatsu = Brain and Development, vol. 41, no. 1, 2009, pp. 5-10.
Shintaku H. [Biopterin and child neurologic disease]. No To Hattatsu. 2009;41(1):5-10.
Shintaku, H. (2009). [Biopterin and child neurologic disease]. No to Hattatsu = Brain and Development, 41(1), 5-10.
Shintaku H. [Biopterin and Child Neurologic Disease]. No To Hattatsu. 2009;41(1):5-10. PubMed PMID: 19172809.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - [Biopterin and child neurologic disease]. A1 - Shintaku,Haruo, PY - 2009/1/29/entrez PY - 2009/1/29/pubmed PY - 2009/3/31/medline SP - 5 EP - 10 JF - No to hattatsu = Brain and development JO - No To Hattatsu VL - 41 IS - 1 N2 - Tetrahydrobiopterin (BH4) deficiencies are disorders affecting phenylalanine metabolism in the liver and neurotransmitter biosynthesis in the brain. BH4 is the essential cofactor in the enzymatic hydroxylation of 3 aromatic amino acids (phenylalanine, tyrosine, and tryptophan). BH4 is synthesized from guanosine triphosphate (GTP), catalyzed by GTP cyclohydrolase I (GTPCH), 6-pyruvoyl-tetrahydropterin synthase, and sepiapterin reductase (SR), and in aromatic amino acids, the hydoxylating system is regenerated by pterin-4a-carbinolamine dehydrolase and dihydropteridine reductase (DHPR). BH4 deficiency has been diagnosed in patients with hyperphenylalaninemia (HPA) by neonatal mass-screening based on BH4 oral-loading tests, analysis of urinary or serum pteridines, and measurement of DHPR activity in blood using a Guthrie card. BH4 deficiency without treatment causes combined symptoms of HPA and neurotransmitter (dopamine, norepinephrine, epinephrine, and serotonin) deficiency, such as red hair, psychomotor retardation, and progressive neurological deterioration. However, autosomal dominant GTPCH deficiency and autosomal recessive SR deficiency leads to BH4 and neurotransmitter deficiency without HPA and may not be detected by neonatal screening for phenylketonuria. The former is Segawa's disease, which is characterized by dopa-responsive dystonia with marked diurnal fluctuation and is caused by a defect of GTPCH, and the latter is SR deficiency, which is characterized by progressive psychomotor retardation, dystonia, and severe dopamine and serotonin deficiencies. Biochemical diagnosis is performed by the measurement of neopterin and biopterin levels, since both are low in Segawa disease, and the biopterin level is high in SR deficiency in cerebrospinal fluid. We must consider metabolic disorders of biopterin in child neurologic diseases with dystonia. SN - 0029-0831 UR - https://wwww.unboundmedicine.com/medline/citation/19172809/[Biopterin_and_child_neurologic_disease]_ L2 - http://www.medicalonline.jp/meteo_linkout.php?issn=0029-0831&volume=41&issue=1&spage=5 DB - PRIME DP - Unbound Medicine ER -
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