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GTR Home > Conditions/Phenotypes > Dihydropteridine reductase deficiency

Dihydropteridine reductase deficiency

Synonyms
BH4-Deficient Hyperphenylalaninemia C; HYPERPHENYLALANINEMIA, TETRAHYDROBIOPTERIN-DEFICIENT, DUE TO DHPR DEFICIENCY; Hyperphenylalaninemia due to dihydropteridine reductase deficiency; Hyperphenylalaninemia, BH-4-deficient, C; Phenylketonuria II; Phenylketonuria type 2; Quinoid dihydropteridine reductase deficiency
Modes of inheritance
Autosomal recessive inheritance (Orphanet)

Summary

Tetrahydrobiopterin deficiency is a rare disorder characterized by a shortage (deficiency) of a molecule called tetrahydrobiopterin or BH4. This condition alters the levels of several substances in the body, including phenylalanine. Phenylalanine is a building block of proteins (an amino acid) that is obtained through the diet. It is found in foods that contain protein and in some artificial sweeteners. High levels of phenylalanine are present from early infancy in people with untreated tetrahydrobiopterin deficiency. This condition also alters the levels of chemicals called neurotransmitters, which transmit signals between nerve cells in the brain.\n\nInfants with tetrahydrobiopterin deficiency appear normal at birth, but medical problems ranging from mild to severe become apparent over time. Signs and symptoms of this condition can include intellectual disability, progressive problems with development, movement disorders, difficulty swallowing, seizures, behavioral problems, and an inability to control body temperature. [from MedlinePlus Genetics]

Available tests

47 tests are in the database for this condition.

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Clinical tests (47 available)

Biochemical Genetics Tests

Molecular Genetics Tests

Genes See tests for all associated and related genes

  • Also known as: DHPR, HDHPR, PKU2, SDR33C1, QDPR
    Summary: quinoid dihydropteridine reductase

Clinical features

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Imported from Human Phenotype Ontology (HPO)

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Reviews

Clinical resources

Practice guidelines

  • ACMG ACT, 2022
    American College of Medical Genetics and Genomics, Newborn Screening ACT Sheet, Elevated Phenylalanine, Phenylalanine hydroxylase deficiency (PAH), 2022
  • ACMG Algorithm, 2022
    American College of Medical Genetics and Genomics, Algorithm, PAH deficiency: Elevated Phenylalanine, 2022

Molecular resources

Consumer resources

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