GENE REFERENCE / HGNC:1583

CCND2

cyclin D2

protein-coding gene12p13.32Gene information

What does this gene do?

The CCND2 gene provides instructions for making a protein called cyclin D2. Cyclins are a family of proteins that control how cells proceed through the multi-step cycle of cell division. Cyclin D2 helps to regulate a step in the cycle called the G1-S transition, in which the cell moves from the G1 phase, when cell growth occurs, to the S phase, when the cell's DNA is copied (replicated) in preparation for cell division. Cyclin D2's role in the cell division cycle makes it a key controller of the rate of cell growth and division (proliferation) in the body.

The cyclin D2 protein is regulated by a chemical signaling pathway called the PI3K-AKT-mTOR pathway. This signaling influences many critical cell functions, including the creation (synthesis) of new proteins, cell proliferation, and the survival of cells. The PI3K-AKT-mTOR pathway is essential for the normal development of many parts of the body, including the brain.

Source: MedlinePlus, National Library of Medicine. Source publication: 2023-03-20. Source review: 2017-01.

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
megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome 3MONDO:0014408 · Evaluated 2025-05-27	Autosomal dominant	DefinitiveBrain Malformations 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: 254
Submissions for variants in or overlapping this gene: 377
Submissions explicitly reporting this gene: 301
Alleles reported pathogenic / likely pathogenic: 17
VariationIDs with uncertain significance: 84
VariationIDs with conflicting classifications: 5

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 CCND2?

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 17 alleles in CCND2 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 CCND2.

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

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