Tetrahydrobiopterin deficiency (THBD, BH4D) is a rare metabolic disorder that increases the blood levels of phenylalanine. Phenylalanine is an amino acid obtained normally through the diet, but can be harmful if excess levels build up, causing intellectual disability and other serious health problems. In healthy individuals, it is metabolised (hydroxylated) into tyrosine, another amino acid, by phenylalanine hydroxylase. However, this enzyme requires tetrahydrobiopterin as a cofactor and thus its deficiency slows phenylalanine metabolism.
High levels of phenylalanine are present from infancy in people with untreated tetrahydrobiopterin (THB, BH4) deficiency. The resulting signs and symptoms range from mild to severe. Mild complications may include temporary low muscle tone. Severe complications include intellectual disability, movement disorders, difficulty swallowing, seizures, behavioral problems, progressive problems with development, and an inability to control body temperature.
It was first characterized in 1975.[1]
^Ponzone A, Spada M, Ferraris S, Dianzani I, de Sanctis L (2004). "Dihydropteridine reductase deficiency in man: from biology to treatment". Med Res Rev. 24 (2): 127–50. doi:10.1002/med.10055. PMID 14705166. S2CID 35797603.
and 22 Related for: Tetrahydrobiopterin deficiency information
Tetrahydrobiopterindeficiency (THBD, BH4D) is a rare metabolic disorder that increases the blood levels of phenylalanine. Phenylalanine is an amino acid...
indicated in tetrahydrobiopterindeficiency caused by GTP cyclohydrolase I (GTPCH) deficiency, or 6-pyruvoyltetrahydropterin synthase (PTPS) deficiency. Also...
of phenylalanine. A rarer form of hyperphenylalaninemia is tetrahydrobiopterindeficiency, which occurs when the PAH enzyme is normal, and a defect is...
Dihydropteridine reductase deficiency (DHPRD) is a genetic disorder affecting the tetrahydrobiopterin (BH4) synthesis pathway, inherited in the autosomal...
synthesis of tetrahydrobiopterin, and, as a consequence, of dopamine. This condition is one of the six known causes of tetrahydrobiopterindeficiency and is...
dopamine and serotonin. Deficiency of tetrahydrobiopterin can cause toxic buildup of phenylalanine (phenylketonuria) as well as deficiencies of dopamine, norepinephrine...
QDPR gene cause dihydropteridine reductase deficiency, one of the subtypes of tetrahydrobiopterindeficiency. More than 30 disorder-causing mutations in...
E, et al. (September 2018). "5,10-methenyltetrahydrofolate synthetase deficiency causes a neurometabolic disorder associated with microcephaly, epilepsy...
autosomal recessive GTP cyclohydrolase I deficiency was one of the six known causes of tetrahydrobiopterindeficiency. It is also considered part of the spectrum...
gene are associated with methylenetetrahydrofolate reductase deficiency. Complex I deficiency with recessive spastic paraparesis has also been linked to...
methionine (SAMe), recycles the inactive dihydrobiopterin (BH2) into tetrahydrobiopterin (BH4), the necessary cofactor in various steps of monoamine synthesis...
activity but have a deficiency in dihydropteridine reductase (DHPR), an enzyme required for the regeneration of tetrahydrobiopterin (THB or BH4), a cofactor...
cause pterin-4 alpha-carbinolamine dehydratase deficiency, one of the forms of tetrahydrobiopterindeficiency. PCBD1 has been shown to interact with DYRK1B...
does so using molecular oxygen (O2), as well as iron (Fe2+) and tetrahydrobiopterin as cofactors. L-DOPA is a precursor for dopamine, which, in turn...
explanation is that vitamin C increases intracellular concentrations of tetrahydrobiopterin, an endothelial nitric oxide synthase cofactor that promotes the...
[citation needed] GTPCH (GCH1) and tetrahydrobiopterin were found to protect against cell death by ferroptosis. Tetrahydrobiopterin (BH4) acts as a potent, diffusable...
Global Information
