GENE REFERENCE / HGNC:4689
GUCY2D
guanylate cyclase 2D, retinal
What does this gene do?
The GUCY2D gene provides instructions for making a protein that plays an essential role in normal vision. This protein is found in the retina, which is the specialized tissue at the back of the eye that detects light and color. Within the retina, the GUCY2D protein is located in light-detecting cells called photoreceptors. The retina contains two types of photoreceptor cells: rods and cones. Rods are needed for vision in low light, while cones are needed for vision in bright light, including color vision.
The GUCY2D protein is involved in a process called phototransduction. When light enters the eye, it stimulates specialized pigments called opsins that "hold" a vitamin A molecule in photoreceptor cells. This stimulation triggers a series of chemical reactions that close the open channel in the cell membranes of rod and cone cells. This closure produces an electrical signal, which is then interpreted by the brain as vision.
Once photoreceptors have been stimulated by light, they must return to their resting (or "dark") state before they can be stimulated again. The GUCY2D protein is involved in a chemical reaction that re-opens the cell membrane channels that helps return photoreceptors to their dark state after light exposure.
Related condition topics
MedlinePlus mentions this gene in the condition pages below. These links alone do not show that the gene causes a condition.
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 |
|---|---|---|
| GUCY2D-related dominant retinopathyMONDO:0100441 · Evaluated 2022-05-28 | Autosomal dominant | DefinitiveRetina Gene Curation Expert Panel |
| GUCY2D-related recessive retinopathyMONDO:0100453 · Evaluated 2022-03-27 | Autosomal recessive | DefinitiveRetina 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
- 1,847
- Submissions for variants in or overlapping this gene
- 2,997
- Submissions explicitly reporting this gene
- 2,857
- Alleles reported pathogenic / likely pathogenic
- 284
- VariationIDs with uncertain significance
- 737
- VariationIDs with conflicting classifications
- 60
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 ↗
YOUR DNA FILE
Can your DNA file tell you about GUCY2D?
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 284 alleles in GUCY2D 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 GUCY2D.
BioDecode cannot fill gaps in your test, diagnose a condition or replace clinical testing.
Sources and dates
The source information on this page last changed on 2026-10-10.
HGNC Source details
Source release: Fri, 09 Oct 2026 13:40:45 GMT
Source record updated: 2023-06-14
SHA-256: e4cd9c6d7120051b80e5e61d2aeb98bd6a541ddd21f428a6eab922c11242e053
MedlinePlus Source details
Source release: Sat, 10 Oct 2026 05:16:07 GMT
Source publication: 2022-10-06
Source review: 2022-10
SHA-256: fdc8bd614310c12718379cef6569962e5d0e791cecabcc355b53a72816ac263a
ClinVar Source details
Source release: Sun, 04 Oct 2026 13:15:29 GMT
SHA-256: 126d9e5bded1d43c0380ac6684c86f9aab056d2ff2be93d743e408ed917ae558
ClinGen Source details
Source release: Sat, 10 Oct 2026 09:49:14 GMT
SHA-256: 5bbc9404c72cc21d80e36ea4c49380231755850af5c34064262adceb74881af6
About the library sources · Latest validated release · Record 93b9040a1d9d