DDC

Chr 7

dopa decarboxylase

Also known as: AADC

The encoded protein catalyzes the decarboxylation of L-3,4-dihydroxyphenylalanine (DOPA) to dopamine, L-5-hydroxytryptophan to serotonin and L-tryptophan to tryptamine. Defects in this gene are the cause of aromatic L-amino-acid decarboxylase deficiency (AADCD). AADCD deficiency is an inborn error in neurotransmitter metabolism that leads to combined serotonin and catecholamine deficiency. Multiple alternatively spliced transcript variants encoding different isoforms have been identified for this gene. [provided by RefSeq, Jun 2011]

GeneReviewsResearchGenerating clinical summary…

Primary Disease Associations & Inheritance

UniProtAromatic L-amino-acid decarboxylase deficiency

Clinical highlights

Gene-disease validity (ClinGen)
aromatic L-amino acid decarboxylase deficiency · ARDefinitivesufficient evidence for diagnostic panels
Interpreting a novel variant
Loss of function is the curated mechanism (Gene2Phenotype), though the gene is not strongly LoF-constrained in the population — weigh truncating variants against that tolerance.Curated gene-level mechanism — a prior for triage, not a per-variant call.
12
Active trials
315
Pubs (1 yr)
P/LP submissions
P/LP missense
0.92
LOEUF
LOF
Mechanism· G2P
📖
GeneReview available — DDC
Authoritative clinical overview · Recommended first read
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Some data sources returned errors (1)

omim: Error: OMIM fetch failed: 429

  • eladocagene exuparvovec (Upstaza/Kebilidi)
    AAV gene therapyApproved · EMA 2022 / FDA 2024

    AAV2-hAADC delivered to the putamen.

    Delivery: Bilateral stereotactic intraputaminal infusionEligibility: ≥18 months with AADC deficiency

Therapeutic landscape as of 2026-07. Educational only. Investigational ≠ available; not medical advice or eligibility. Approved entries are precise; investigational program names/phases are conservative and move fast. Curated from FDA/EMA approvals and the clinical-trial literature; verify against current labeling + ClinicalTrials.gov.

ClinicalTrials.gov

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint?
0.92LOEUF
pLI 0.000
Z-score 1.90
OE 0.60 (0.410.92)
Tolerant

Typical tolerance to LoF variation

Missense Constraint?
0.41Z-score
OE missense 0.93 (0.841.03)
258 obs / 277.2 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios?
LoF OE?0.60 (0.410.92)
00.351.4
Missense OE?0.93 (0.841.03)
00.61.4
Synonymous OE?1.09
01.21.6
LoF obs/exp: 16 / 26.5Missense obs/exp: 258 / 277.2Syn Z: -0.72

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

DDC · protein map & ClinVar variants

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

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

Anatomic Stage II Breast Cancer AJCC v8Anatomic Stage IIA Breast Cancer AJCC v8Anatomic Stage IIB Breast Cancer AJCC v8

CompassHER2-pCR: Decreasing Chemotherapy for Breast Cancer Patients After Pre-surgery Chemo and Targeted Therapy

ACTIVE NOT RECRUITING
NCT04266249Phase PHASE2ECOG-ACRIN Cancer Research GroupStarted 2020-03-13
DocetaxelLumpectomyMastectomy
Stage II Colorectal Cancer AJCC v8Stage III Colorectal Cancer AJCC v8

Duloxetine to Prevent Oxaliplatin-Induced Peripheral Neuropathy in Patients With Stage II-III Colorectal Cancer

ACTIVE NOT RECRUITING
NCT04137107Phase PHASE2, PHASE3Alliance for Clinical Trials in OncologyStarted 2020-06-17
OxaliplatinDuloxetine HydrochlorideDuloxetine
Plasma Cell Myeloma

Bortezomib or Carfilzomib With Lenalidomide and Dexamethasone in Treating Patients With Newly Diagnosed Multiple Myeloma

ACTIVE NOT RECRUITING
NCT01863550Phase PHASE3ECOG-ACRIN Cancer Research GroupStarted 2013-12-06
BortezomibCarfilzomibDexamethasone
Intracranial MeningiomaRecurrent MeningiomaNF2 Gene Mutation

Vismodegib, FAK Inhibitor GSK2256098, Capivasertib, and Abemaciclib in Treating Patients With Progressive Meningiomas

RECRUITING
NCT02523014Phase PHASE2Alliance for Clinical Trials in OncologyStarted 2015-09-28
VismodegibFAK Inhibitor GSK2256098Capivasertib
Stage II Breast CancerStage IIIA Breast Cancer

Comparison of Axillary Lymph Node Dissection With Axillary Radiation for Patients With Node-Positive Breast Cancer Treated With Chemotherapy

ACTIVE NOT RECRUITING
NCT01901094Phase PHASE3Alliance for Clinical Trials in OncologyStarted 2014-02-24
Axillary Lymph Node Dissection (ALND)Nodal Radiation TherapyAxillary Radiation Therapy
Breast Ductal Carcinoma In SituInvasive Breast CarcinomaStage II Breast Cancer AJCC v6 and v7

Breast Cancer WEight Loss Study (BWEL Study)

ACTIVE NOT RECRUITING
NCT02750826Phase PHASE3Alliance for Clinical Trials in OncologyStarted 2016-09-16
Health Education ProgramWeight Loss Intervention
Breast CancerCognitive Impairments

Cognitive Training for Cancer Related Cognitive Impairment in Breast Cancer Survivors

ACTIVE NOT RECRUITING
NCT05896189Phase NANRG OncologyStarted 2024-02-29
Arm 1: Computerized Cognitive Training-Global Stimulation GamesArm 2: Computerized Cognitive Training-Neuroplasticity Games
Anatomic Stage I Breast Cancer AJCC v8Anatomic Stage II Breast Cancer AJCC v8Anatomic Stage III Breast Cancer AJCC v8

Monitoring Symptoms to Help Young Women Take Hormone Therapy for Stage I-III Breast Cancer, ASPEN Study

ACTIVE NOT RECRUITING
NCT05568472Phase NASWOG Cancer Research NetworkStarted 2023-03-29
Best PracticeBiospecimen CollectionEndocrine Drug Therapy
Breast Carcinoma In SituInvasive Breast CarcinomaStage I Breast Cancer AJCC v7

Testing MK-3475 (Pembrolizumab) as Adjuvant Therapy for Triple Receptor-Negative Breast Cancer

ACTIVE NOT RECRUITING
NCT02954874Phase PHASE3National Cancer Institute (NCI)Started 2017-01-18
Biospecimen CollectionLaboratory Biomarker AnalysisPatient Observation
Lung Non-Small Cell CarcinomaLung Non-Small Cell Squamous CarcinomaLung Non-Squamous Non-Small Cell Carcinoma

Testing the Addition of a Type of Drug Called Immunotherapy to the Usual Chemotherapy Treatment for Non-small Cell Lung Cancer, an ALCHEMIST Treatment Trial (Chemo-IO [ACCIO])

RECRUITING
NCT04267848Phase PHASE3National Cancer Institute (NCI)Started 2020-06-16
Biospecimen CollectionCarboplatinCisplatin
Aromatic L-amino Acid Decarboxylase Deficiency

A Trial to Evaluate Safety and Efficacy of a Product Named VGN-R09b in Severe AADC Deficiency

ACTIVE NOT RECRUITING
NCT06432140Phase PHASE2, PHASE3Shanghai Vitalgen BioPharma Co., Ltd.Started 2024-07-02
VGN-R09b injection
Cardiomyopathy

Natural History Study in Pediatric Patients With MYBPC3 Mutation-associated Cardiomyopathy

ACTIVE NOT RECRUITING
NCT05112237Tenaya TherapeuticsStarted 2021-11-01