PHYH (Phytanoyl-CoA 2-Hydroxylase)
Peroxisomal enzyme involved in phytanic acid alpha-oxidation; mutations cause Refsum disease
Gene Information Card
| Symbol | PHYH |
|---|---|
| Full Name | Phytanoyl-CoA 2-Hydroxylase |
| Gene Type | Protein coding |
| Chromosomal Location | 10p13 |
| NCBI Gene ID | 5264 ncbi.nlm.nih.gov/gene/5264 |
| Ensembl ID | ENSG00000107537 |
| UniProt ID | O14832 |
| OMIM ID | 602026 |
| HGNC ID | 8940 |
| Aliases | PAHX, PHYH1, RD, LN1 |
Description
PHYH encodes phytanoyl-CoA 2-hydroxylase, a peroxisomal enzyme that catalyzes the first step of alpha-oxidation of phytanic acid, converting phytanoyl-CoA to 2-hydroxyphytanoyl-CoA. This process is essential for the degradation of phytanic acid, a branched-chain fatty acid derived from dietary chlorophyll. Deficiency due to biallelic mutations leads to accumulation of phytanic acid and causes adult-onset Refsum disease (ARD).
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Refsum disease (adult-onset) | Loss of PHYH function impairs alpha-oxidation, leading to phytanic acid accumulation in tissues | ClinVar, OMIM #266500 |
| Hereditary motor and sensory neuropathy (HMSN) type IV | Same mechanism as Refsum disease; phenotypic overlap | OMIM #266500 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 12.3 | Medium |
| Kidney | 8.7 | Medium |
| Small intestine | 6.5 | Low |
| Heart | 4.2 | Low |
| Brain | 2.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 10.1 | Hepatocyte line |
| HEK 293 | 5.4 | Embryonic kidney |
| SH-SY5Y | 1.8 | Neuroblastoma |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.135-2A>G | Splice acceptor | ~30% of Refsum alleles | Loss of function |
| p.Arg275Trp | Missense | ~15% | Reduced enzyme activity |
| p.Arg250X | Nonsense | ~10% | Premature truncation, loss of function |
| c.678+1G>A | Splice donor | ~8% | Loss of function |
Mutation functional classification
Loss of Function (LOF)
Majority of PHYH mutations cause complete or partial loss of enzyme activity, leading to phytanic acid accumulation.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
No dominant-negative mutations reported; disease is autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
| • phytanoyl-CoA dioxygenase activity | • iron ion binding |
| • alpha-oxidation | • peroxisome |
| • fatty acid catabolic process |
Pathways
• Alpha-oxidation of phytanic acid (Reactome: R-HSA-389887)
• Peroxisomal lipid metabolism
Protein Summary
Phytanoyl-CoA 2-hydroxylase is a 338-amino acid peroxisomal protein that contains a non-heme iron center and uses 2-oxoglutarate as a co-substrate. It hydroxylates phytanoyl-CoA at the 2-position, enabling subsequent decarboxylation and chain shortening. The enzyme is highly expressed in liver and kidney, consistent with its role in lipid metabolism.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| PHYH Knockout HEK293 Cell Line | EDJ-KQ5454 | Human | 5264 | Details Get a Quote |
| PHYHIP Knockout HEK293 Cell Line | EDJ-KQ6754 | Human | 9796 | Details Get a Quote |
| PHYHIPL Knockout HEK293 Cell Line | EDJ-KQ10095 | Human | 84457 | Details Get a Quote |
| PHYHD1 Knockout HEK293 Cell Line | EDJ-KQ11765 | Human | 254295 | Details Get a Quote |
| PHYHIP Knockout HeLa Cell Line | EDJ-KQ31179 | Human | 9796 | Details Get a Quote |
| PHYHD1 Knockout HeLa Cell Line | EDJ-KQ40156 | Human | 254295 | Details Get a Quote |
| PHYH Knockout HeLa Cell Line | EDJ-KQ27399 | Human | 5264 | Details Get a Quote |
| PHYH Knockout A-549 Cell Line | EDJ-KQ28644 | Human | 5264 | Details Get a Quote |
| PHYH Knockout HCT 116 Cell Line | EDJ-KQ28645 | Human | 5264 | Details Get a Quote |
| PHYHIPL Knockout HeLa Cell Line | EDJ-KQ57597 | Human | 84457 | Details Get a Quote |
| PHYHIP Knockout A-549 Cell Line | EDJ-KQ63734 | Human | 9796 | Details Get a Quote |
| PHYHIPL Knockout A-549 Cell Line | EDJ-KQ66094 | Human | 84457 | Details Get a Quote |
| PHYHD1 Knockout A-549 Cell Line | EDJ-KQ67724 | Human | 254295 | Details Get a Quote |
| PHYHIP Knockout HCT 116 Cell Line | EDJ-KQ72193 | Human | 9796 | Details Get a Quote |
| PHYHIPL Knockout HCT 116 Cell Line | EDJ-KQ74516 | Human | 84457 | Details Get a Quote |
Displaying Records 1 To 15 Of 16 Records
