PAH

Chr 12AR

phenylalanine hydroxylase

The encoded phenylalanine hydroxylase enzyme hydroxylates phenylalanine to tyrosine as the rate-limiting step in phenylalanine catabolism. Mutations cause autosomal recessive phenylketonuria and milder hyperphenylalaninemia through deficiency of enzyme activity. Loss of function mutations result in accumulation of phenylalanine and its metabolites, leading to intellectual disability if untreated.

OMIMResearchSummary from RefSeq, OMIM, Mechanism
LOFmechanismARLOEUF 1.502 OMIM phenotypes
VCEP Guidelines: PhenylketonuriaReleased
ClinGen Panel
Clinical SummaryPAH
🧬
Gene-Disease Validity (ClinGen)
phenylketonuria · ARDefinitive

Definitive — sufficient evidence for diagnostic panels

Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
💊
Clinical Trials
12 active or recruiting trials — potential therapeutic options may be available
Some data sources returned errors (1)

ncbi: Error: NCBI fetch failed: 429 https://eutils.ncbi.nlm.nih.gov/entrez/eutils/esearch.fcgi

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
1.50LOEUF
pLI 0.000
Z-score -0.59
OE 1.12 (0.841.50)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint
-0.65Z-score
OE missense 1.12 (1.011.24)
271 obs / 242.6 exp
Tolerant

Tolerant to missense variation

Observed / Expected Ratios
LoF OE1.12 (0.841.50)
00.351.4
Missense OE1.12 (1.011.24)
00.61.4
Synonymous OE1.11
01.21.6
LoF obs/exp: 32 / 28.6Missense obs/exp: 271 / 242.6Syn Z: -0.83
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitivePAH-related phenylketonuria (PKU)LOFAR

Predictions shown for reference only — model trained on dominant genes, not applicable to AR conditions.

DN
0.6550th %ile
GOF
0.5464th %ile
LOF
0.3453th %ile

The Badonyi & Marsh prediction model was trained exclusively on dominant disease genes. Predictions are not reliable for genes with autosomal recessive inheritance and are shown at reduced opacity for reference only.

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

PAH · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

Idiopathic Pulmonary Arterial HypertensionHeritable Pulmonary Arterial HypertensionUnaffected Mutation Carriers: Healthy Participants With a Known BMPR2 Gene Mutation and Normal Pulmonary Pressure and RV Function on Echo

Risk and Resilience in Pulmonary Arterial Hypertension and Genetically Susceptible Individuals

RECRUITING
NCT05584722Vanderbilt University Medical CenterStarted 2022-11-01
Early Breast CancerTriple Negative Breast Cancer

Trial for Treatment of High Risk BC With Two Sequences of Neoadjuvant Chemotherapy With Pembrolizumab

NOT YET RECRUITING
NCT06371807Phase PHASE2Fundacao ChampalimaudStarted 2024-07
Pembrolizumab injection
Estrogen Receptor NegativeEstrogen Receptor PositiveHER2/Neu Negative

Paclitaxel & Cyclophosphamide With or Without Trastuzumab Before Surgery in Treating Previously Untreated Breast Cancer

ACTIVE NOT RECRUITING
NCT01750073Phase PHASE2University of NebraskaStarted 2012-12-07
CyclophosphamideDoxorubicin HydrochlorideLaboratory Biomarker Analysis
Breast AdenocarcinomaEstrogen Receptor- Negative Breast CancerEstrogen Receptor-positive Breast Cancer

Neoadjuvant Pembrolizumab + Decitabine Followed by Std Neoadj Chemo for Locally Advanced HER2- Breast Ca

ACTIVE NOT RECRUITING
NCT02957968Phase PHASE2Virginia Commonwealth UniversityStarted 2017-01-24
DoxorubicinCyclophosphamidePaclitaxel
Episodic MigraineChronic MigraineMedication Overuse Headache

i-NEED: NEw migrainE Drugs Database

RECRUITING
NCT07103694IRCCS San Raffaele RomaStarted 2022-03-24
anti-CGRP monoclonal antibodiesgepantscombination of sumatriptan and naproxen
LeukemiaMyeloid LeukemiaMonocytic Leukemia

Mitoxantrone for Venetoclax Resistant Acute Myeloid Leukemia

RECRUITING
NCT06429449Phase PHASE1University of Colorado, DenverStarted 2024-07-21
VenetoclaxAzacitidineMitoxantrone
Acute Myeloid LeukemiaAML, AdultAML With Gene Mutations

Revumenib in Combination With 7+3 + Midostaurin in AML

RECRUITING
NCT06313437Phase PHASE1Richard Stone, MDStarted 2024-12-06
RevumenibMidostaurinCytarabine
Opioid Use DisorderPregnancy Related

Predicting and Preventing Adverse Maternal and Child Outcomes of Opioid Use Disorder in Pregnancy

RECRUITING
NCT05942313Ilana HullStarted 2023-08-28
Buprenorphine/ Methadone exposure
HIV InfectionMature T-Cell and NK-Cell Non-Hodgkin LymphomaPlasmablastic Lymphoma

Gene Therapy in Treating Patients With Human Immunodeficiency Virus-Related Lymphoma Receiving Stem Cell Transplant

ACTIVE NOT RECRUITING
NCT02797470Phase PHASE1, PHASE2AIDS Malignancy ConsortiumStarted 2016-06-23
Autologous Hematopoietic Stem Cell TransplantationCarmustineCytarabine
Breast CancerTriple Negative Breast Neoplasms

NordicTrip, a Translational Study of Preoperative Chemotherapy in TNBC

ACTIVE NOT RECRUITING
NCT04335669Phase PHASE3Lund University HospitalStarted 2019-12-20
epirubicin, cyclophosphamide, paclitaxel, carboplatin, pembrolizumabepirubicin, cyclophosphamide, capecitabine, paclitaxel, carboplatin, pembrolizumab
Systemic SclerosisScleroderma

Determine Effectiveness of Anifrolumab In SYstemic Sclerosis (DAISY)

ACTIVE NOT RECRUITING
NCT05925803Phase PHASE3AstraZenecaStarted 2023-11-08
Anifrolumab (blinded)Placebo (blinded)Anifrolumab (unblinded, open label)
Sickle Cell DiseaseDyslipidemiaComplication

Lipid Balance in Adult Sickle Cell Patients

ACTIVE NOT RECRUITING
NCT05780775Phase NACentre Hospitalier Universitaire de la GuadeloupeStarted 2022-11-30
HDL2
Clinical Literature
Open Research Assistant →