Meyahealth
HomeGeneticsGeneGNAT1 gene
Back to Gene
GNAT1 gene
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

GNAT1 gene

The GNAT1 gene provides instructions for making a protein essential for transmitting visual signals from the eye to the brain in low-light conditions.

Normal Function

The GNAT1 gene provides instructions for making a protein called alpha (α)-transducin. This protein is one part (the alpha subunit) of a protein complex called transducin. There are several versions of transducin made up of different subunits. Each version is found in a particular cell type in the light-sensitive tissue at the back of the eye (the retina), where it plays a role in transmitting visual signals from the eye to the brain.

The transducin complex that contains α-transducin is found only in specialized light receptor cells in the retina called rods. Rods are responsible for vision in low-light conditions. When light enters the eye, a rod cell protein called rhodopsin is turned on (activated), which then activates α-transducin. Once activated, α-transducin breaks away from the transducin complex in order to activate another protein called cGMP-PDE, which triggers a series of chemical reactions that create electrical signals. These signals are transmitted from rod cells to the brain, where they are interpreted as vision.

Health Conditions Related to Genetic Changes

Autosomal dominant congenital stationary night blindness

At least two mutations in the GNAT1 gene have been found to cause autosomal dominant congenital stationary night blindness, which is characterized by the inability to see in low light.

  • One of these mutations impairs the protein's ability to activate cGMP-PDE.
  • The other mutation results in a protein that is constantly turned on (constitutively activated).

Both of these mutations disrupt the pathway that creates visual signals to be sent from rod cells to the brain. A nonfunctional α-transducin protein stops the signaling pathway. When α-transducin is constitutively activated, the signals that the rod cells send to the brain are constantly occurring, even in bright light. Visual information from rod cells is then perceived by the brain as not meaningful, resulting in night blindness.

Other Names for This Gene

  • CSNBAD3
  • GBT1
  • GNAT1_HUMAN
  • GNATR
  • guanine nucleotide binding protein (G protein), alpha transducing activity polypeptide 1
  • guanine nucleotide-binding protein G(t) subunit alpha-1
  • guanine nucleotide-binding protein G(T), alpha-1 subunit
  • rod-type transducin alpha subunit
  • transducin alpha-1 chain
  • transducin, rod-specific

Frequently Asked Questions

There is no cure that restores normal rod function, but management focuses on environmental adaptations. Using brighter lighting, high‑contrast visual aids, and avoiding glare can help. Some patients benefit from low‑vision rehabilitation services. Research into gene therapy is ongoing but not yet available clinically.
Patients with GNAT1 mutations typically have difficulty seeing in low‑light or dim conditions from birth or early childhood. They may report that streets at night appear dim or that they need brighter lights to read. Vision in bright light is usually normal, and the condition does not progress over time. If these symptoms are present, an eye specialist may suspect a rod‑cell disorder.
The condition is autosomal dominant, meaning a single copy of the mutated gene can cause the disorder. A parent with the mutation has a 50% chance of passing it to each child. Genetic counseling can help families understand risks and discuss options such as prenatal testing or pre‑implantation genetic diagnosis.
Diagnosis starts with a detailed eye exam, including visual acuity and night vision tests. An electroretinogram (ERG) can show reduced rod responses while cone responses remain normal. Genetic testing that sequences the GNAT1 gene confirms the specific mutation.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.

Meyahealth

Ⓒ 2026. All rights reserved by MEYA

About UsTerms & PolicyFAQ