GENE REFERENCE / HGNC:2719

DDC

dopa decarboxylase

protein-coding gene7p12.2-p12.1Gene information

What does this gene do?

The DDC gene provides instructions for making the aromatic l-amino acid decarboxylase (AADC) enzyme, which plays an important role in the brain and nervous system. This enzyme is involved in the final step of the chemical pathways that produce dopamine and serotonin, which are two types of neurotransmitters. Neurotransmitters are chemical messengers that transmit signals between nerve cells (neurons) and other cells in the body. Dopamine is involved in the creation of two additional neurotransmitters called norepinephrine and epinephrine.

The AADC enzyme plays a role in the two-step process that is used to create dopamine. First, the protein building block (amino acid) tyrosine is converted into a molecule called L-dopa. The AADC enzyme then removes a molecular structure called a carboxyl group (which consists of a carbon atom, two oxygen atoms, and a hydrogen atom) from L-dopa, creating dopamine. A similar process is used to make serotonin. The amino acid tryptophan is converted to 5-hydroxytryptophan before the AADC enzyme removes a carboxyl group, producing serotonin.

Source: MedlinePlus, National Library of Medicine. Source publication: 2024-05-13. Source review: 2024-05.

ClinGen reviews

ClinGen reviews the evidence linking a particular gene to a condition. Each rating below describes the strength of that link. It does not classify a variant in your DNA file.

Condition	Inheritance	Evidence
aromatic L-amino acid decarboxylase deficiencyMONDO:0012084 · Evaluated 2022-02-25	Autosomal recessive	DefinitiveGeneral Inborn Errors of Metabolism Gene Curation Expert Panel

ClinVar records

These numbers show what has been submitted to ClinVar. They cannot tell you how likely you are to have a condition.

Submitted alleles: 694
Submissions for variants in or overlapping this gene: 1,044
Submissions explicitly reporting this gene: 1,021
Alleles reported pathogenic / likely pathogenic: 100
VariationIDs with uncertain significance: 223
VariationIDs with conflicting classifications: 35

The rows count different things: alleles, submissions or VariationIDs. Their categories can overlap, so do not add them together. Pathogenic/likely pathogenic counts exclude structural variants that merely overlap a gene. A dash in the source means “not reported,” not zero.

NCBI produces the gene-summary file each week using counts recorded at the start of the month. The numbers may differ from those on the live ClinVar website. Read the field definitions ↗

View this gene in ClinVar ↗

YOUR DNA FILE

Can your DNA file tell you about DDC?

From a DNA test kit (such as 23andMe, AncestryDNA or MyHeritage). These kits check a fixed list of about 600,000 to 700,000 positions across your whole genome. ClinVar lists 100 alleles in DDC reported as pathogenic or likely pathogenic. A kit checks only some of these positions, and often none of them.

From whole genome sequencing (a VCF file). Sequencing reads most of your genome. Your file lists the places where your DNA differs from the reference genome. Some regions are hard to sequence, including parts of some genes that have near-identical copies elsewhere, and a VCF file does not record which positions were read well.

If a variant is not in your file, that does not mean you don’t have it.

What BioDecode checks

BioDecode compares every variant in your file with ClinVar, on your own computer. For each match, it shows the ClinVar classification, the review status and the condition it was reported for. Your file is not uploaded.

A ClinVar classification applies to one particular variant and the condition it was reported for. It does not tell you about other variants in DDC.

BioDecode cannot fill gaps in your test, diagnose a condition or replace clinical testing.

Buy BioDecode See a sample report →Check file compatibility →