Traits

Traits linked to QDPR

quinoid dihydropteridine reductase

The Human Phenotype Ontology links 18 traits to QDPR, by body system: features seen in people with one of the gene's rare conditions.

Abnormality of the nervous system

Trait	How often it is seen
Global developmental delay	Always
Intellectual disability	Very often (80–99%)
Choreoathetosis	Not recorded
Dystonia	Not recorded
Epilepsy	Not recorded
Irritability	Not recorded
Jerking	Not recorded
Tremor	Not recorded
Worsening neurological symptoms	Not recorded

Abnormality of the musculoskeletal system

Trait	How often it is seen
Abnormal deposits of calcium in the brain	Not recorded
Low muscle tone	Not recorded
Spasticity and rigidity of muscles	Not recorded

Laboratory abnormality

Trait	How often it is seen
Diminished tissue dihydropteridine reductase activity	Always
Episodic fever	Not recorded
Hyperphenylalaninemia	Not recorded

Abnormality of head or neck

Trait	How often it is seen
Abnormally small head	Very often (80–99%)
Excessive salivation	Not recorded

Abnormality of the digestive system

Trait	How often it is seen
Poor swallowing	Very often (80–99%)

How often is among people with one of the gene's conditions, the most often across them, as the Human Phenotype Ontology records it. These pages describe traits and the research behind them; they are not a diagnosis, and a doctor or genetic counsellor is the person to ask about symptoms.

Where this comes from

The Human Phenotype Ontology, release 2026-09-01: the traits linked to QDPR and how often each is seen. Find out more at hpo.jax.org.

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