Conditions / Genetic
BH4-deficient hyperphenylalaninemia B
info · Genetic
A tetrahydrobiopterin (BH4)-deficient hyperphenylalaninemia that is characterized by hyperphenylalaninemia, depletion of the neurotransmitters dopamine and serotonin, and progressive cognitive and motor deficits that has_material_basis_in homozygous or compoun
A tetrahydrobiopterin (BH4)-deficient hyperphenylalaninemia that is characterized by hyperphenylalaninemia, depletion of the neurotransmitters dopamine and serotonin, and progressive cognitive and motor deficits that has_material_basis_in homozygous or compound heterozygous mutation in the GCH1 gene on chromosome 14q22.2.
Signs and symptoms
- Dystonia
- Seizure
- Hypotonia
- Generalized hypotonia
- Decreased urinary biopterin level
- Increased CSF phenylalanine concentration
- Choreoathetosis
- Feeding difficulties
- Poor suck
- Global developmental delay
Also known as: GTP cyclohydrolase 1 deficiency; HPABH4B; tetrahydrobiopterin-deficient hyperphenylalaninemia B