QDPR Gene (Quinoid Dihydropteridine Reductase)
Key Enzyme in Tetrahydrobiopterin Recycling and Phenylalanine Metabolism
Gene Information Card
| Symbol | QDPR |
|---|---|
| Full Name | Quinoid Dihydropteridine Reductase |
| Gene Type | Protein coding |
| Chromosomal Location | 4p15.32 |
| NCBI Gene ID | 5860 ncbi.nlm.nih.gov/gene/5860 |
| Ensembl ID | ENSG00000151692 |
| UniProt ID | P09417 |
| OMIM ID | 612676 |
| HGNC ID | 9390 |
| Aliases | DHPR, SDR33C1 |
Description
The QDPR gene encodes quinoid dihydropteridine reductase (DHPR), an enzyme essential for the regeneration of tetrahydrobiopterin (BH4), a cofactor for phenylalanine, tyrosine, and tryptophan hydroxylases. DHPR catalyzes the NADH-dependent reduction of quinoid dihydrobiopterin to BH4, maintaining adequate BH4 levels for aromatic amino acid hydroxylation and neurotransmitter synthesis. Mutations in QDPR cause dihydropteridine reductase deficiency (DHPR deficiency), a form of hyperphenylalaninemia with severe neurological consequences.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Dihydropteridine reductase deficiency (DHPR deficiency) | Loss-of-function mutations in QDPR impair BH4 recycling, leading to accumulation of phenylalanine and deficiency of dopamine and serotonin neurotransmitters. | ClinVar, OMIM #261630 |
| Hyperphenylalaninemia, BH4-deficient, type C | Deficient DHPR activity causes elevated phenylalanine levels despite normal phenylalanine hydroxylase. | OMIM #261630, NCBI Gene |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 12.3 | Medium |
| Kidney | 8.7 | Medium |
| Brain | 6.5 | Low |
| Heart | 5.1 | Low |
| Lung | 4.3 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 14.2 | Hepatocellular carcinoma cell line |
| HEK293 | 9.8 | Embryonic kidney cells |
| SH-SY5Y | 7.1 | Neuroblastoma cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.250G>A (p.Gly84Arg) | Missense | Rare | Loss of enzyme activity; associated with DHPR deficiency |
| c.515G>A (p.Arg172Gln) | Missense | Rare | Reduced catalytic efficiency; pathogenic in ClinVar |
| c.1A>G (p.Met1?) | Start loss | Rare | Complete loss of protein; severe phenotype |
Mutation functional classification
Loss of Function (LOF)
Most QDPR mutations cause loss of enzymatic activity, leading to BH4 deficiency and hyperphenylalaninemia.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
No dominant-negative mutations reported; DHPR deficiency is autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
| • dihydropteridine reductase activity (GO:0004159) | • tetrahydrobiopterin biosynthetic process (GO:0006729) |
| • L-phenylalanine catabolic process (GO:0006559) | • cytoplasm (GO:0005737) |
| • cytosol (GO:0005829) |
Pathways
• Tetrahydrobiopterin (BH4) metabolism (Reactome R-HSA-1474228)
• Phenylalanine and tyrosine metabolism (KEGG hsa00360)
Protein Summary
Quinoid dihydropteridine reductase (DHPR) is a 244-amino acid monomeric enzyme that belongs to the short-chain dehydrogenase/reductase (SDR) family. It uses NADH to reduce quinoid dihydrobiopterin to tetrahydrobiopterin, a critical cofactor for aromatic amino acid hydroxylases. The protein is expressed in liver, kidney, and brain. Defects in DHPR cause severe neurological disease due to neurotransmitter depletion.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| QDPR Knockout HEK293 Cell Line | EDJ-KQ5620 | Human | 5860 | Details Get a Quote |
| QDPR Knockout A-549 Cell Line | EDJ-KQ28925 | Human | 5860 | Details Get a Quote |
| QDPR Knockout HCT 116 Cell Line | EDJ-KQ28926 | Human | 5860 | Details Get a Quote |
| QDPR Knockout HeLa Cell Line | EDJ-KQ28927 | Human | 5860 | Details Get a Quote |
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