OTC

Chr XX-linked

ornithine transcarbamylase

Also known as: OCTD, OTC1, OTCD, OTCase

The protein is a mitochondrial matrix enzyme that catalyzes a key step in the urea cycle, converting ammonia to urea for excretion. Mutations cause ornithine transcarbamylase deficiency, an X-linked disorder that results in hyperammonemia due to impaired ammonia detoxification. The high pLI score indicates the gene is highly intolerant to loss-of-function mutations.

OMIMResearchSummary from RefSeq, OMIM, UniProt
LOFmechanismX-linkedLOEUF 0.411 OMIM phenotype
VCEP Guidelines: Urea Cycle DisordersReleased
ClinGen Panel
Clinical SummaryOTC
🧬
Gene-Disease Validity (ClinGen)
ornithine carbamoyltransferase deficiency · XLDefinitive

Definitive — sufficient evidence for diagnostic panels

Population Constraint (gnomAD)
Moderately constrained gene (pLI 0.87) — some intolerance to loss-of-function variants.
💊
Clinical Trials
12 active or recruiting trials — potential therapeutic options may be available

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Moderate LoF intolerance
LoF Constraint
0.41LOEUF
pLI 0.873
Z-score 3.18
OE 0.13 (0.050.41)
Moderately constrained

More LoF-intolerant than ~75% of genes

Missense Constraint
1.33Z-score
OE missense 0.67 (0.570.81)
89 obs / 131.9 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.13 (0.050.41)
00.351.4
Missense OE0.67 (0.570.81)
00.61.4
Synonymous OE0.97
01.21.6
LoF obs/exp: 2 / 15.5Missense obs/exp: 89 / 131.9Syn Z: 0.19

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

OTC · 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

Microbial ColonizationEye DiseasesOphthalmopathy

Assessment of the Ocular Microbiome in Health and Disease

RECRUITING
NCT05414994Vanderbilt University Medical CenterStarted 2023-09-07
Eye swab
COVID-19COVID

Clinical Validation of the Aptitude Medical Systems Metrix COVID-19 Test

RECRUITING
NCT06744660Phase NAAptitude Medical SystemsStarted 2024-10-17
Aptitude Medical Systems Metrix COVID Test
Impaired Glucose RegulationImpaired Glucose Tolerance (Prediabetes)Prediabetes (Insulin Resistance, Impaired Glucose Tolerance)

Probiotic Impact on Cognitive Performance, and Metabolic Outcomes in Overweight Young Adults With Impaired Glucose Regulation

RECRUITING
NCT07073781Phase NALeeds Beckett UniversityStarted 2025-08-15
Lab4p Probiotic ConsortiumPlacebo
Optical Coherence Tomography (OCT) of the RetinaMutation

Looking for VUS to Confirm Dominant Wolfram-like Syndrome Instead of Recessive Wolfram Syndrome

ACTIVE NOT RECRUITING
NCT07485413Hôpital Necker-Enfants MaladesStarted 2026-03-08
OTC Deficiency

Clinical Study of DTX301 AAV-Mediated Gene Transfer for Ornithine Transcarbamylase (OTC) Deficiency

ACTIVE NOT RECRUITING
NCT05345171Phase PHASE3Ultragenyx Pharmaceutical IncStarted 2022-10-18
DTX301PlaceboOral Corticosteroids
Preterm Birth ComplicationPreterm BirthPreterm Birth Recurrence

Personalized Care for Prenatal Stress Reduction & Prevention of Preterm Birth (PTB) Disparities

NOT YET RECRUITING
NCT06915428Phase NAUniversity of North Carolina, Chapel HillStarted 2026-02-01
Care coordinationElectronic massagesupport gift #1
Ornithine Transcarbamylase (OTC) Deficiency

Long Term Follow Up to Evaluate DTX301 in Adults With Late-Onset OTC Deficiency

ACTIVE NOT RECRUITING
NCT03636438Ultragenyx Pharmaceutical IncStarted 2018-08-30
No Intervention
Persistent Pulmonary Hypertension of the Newborn

PTGS1 Genetic Variation and Increased Risk for Persistent Pulmonary Hypertension of the Newborn

RECRUITING
NCT00710177Medical College of WisconsinStarted 2006-01
Lynch Syndrome I (Site-specific Colonic Cancer)

Finding the Best Dose of Aspirin to Prevent Lynch Syndrome Cancers

NOT YET RECRUITING
NCT02497820Phase PHASE3Tel-Aviv Sourasky Medical CenterStarted 2016-09
Aspirin
Schizophrenia and Related DisordersMitochondrial AlterationCognitive Impairment

MitoQ for Early-phase Schizophrenia-spectrum Disorder and Mitochondrial Dysfunction

RECRUITING
NCT06191965Phase PHASE2, PHASE3Mclean HospitalStarted 2024-06-01
MitoQPlacebo
Fertility DisordersTurner SyndromePremature Ovarian Failure

The Danish TURNER Cryopreservation Study

RECRUITING
NCT05740579Phase NAUniversity of AarhusStarted 2023-01-01
laparoscopic cryopreservation of one ovary
Alcohol Drinking

Nicotinic Receptor Genetic Variation and Alcohol Reward

RECRUITING
NCT03294460Phase PHASE1National Institute on Alcohol Abuse and Alcoholism (NIAAA)Started 2019-06-10
Alcohol (Oral)Alcohol (IV)Alcohol (Ethanol)
Clinical Literature
Open Research Assistant →
Full-Text Mentions
NLP-detected gene mentions in article bodies · via PubTator3
PubTator3
Top 5 full-text resultsSearch PubTator3 ↗