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GATM gene
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

GATM gene

The GATM gene provides instructions for making the enzyme arginine:glycine amidinotransferase, which is essential for the body's production of creatine.

Normal Function

The GATM gene provides instructions for making the enzyme arginine:glycine amidinotransferase. This enzyme participates in the two-step production (synthesis) of the compound creatine from the protein building blocks (amino acids) glycine, arginine, and methionine. Specifically, arginine:glycine amidinotransferase controls the first step of the process. In this step, a compound called guanidinoacetic acid is produced by transferring a cluster of nitrogen and hydrogen atoms called a guanidino group from arginine to glycine. Guanidinoacetic acid is converted to creatine in the second step of the process. Creatine is needed for the body to store and use energy properly.

Health Conditions Related to Genetic Changes

Arginine:glycine amidinotransferase deficiency

At least two mutations in the GATM gene cause arginine:glycine amidinotransferase deficiency, a disorder that involves delayed development, intellectual disability, and in some cases muscle weakness. These mutations result in the production of an abnormally shortened arginine:glycine amidinotransferase enzyme or disrupt how genetic information is pieced together to make a blueprint for producing the enzyme.

GATM gene mutations interfere with the ability of the arginine:glycine amidinotransferase enzyme to participate in creatine synthesis, resulting in a shortage of creatine. The effects of arginine:glycine amidinotransferase deficiency are most severe in organs and tissues that require large amounts of energy, especially the brain.

Other Names for This Gene

  • AGAT
  • AT
  • GATM_HUMAN
  • glycine amidinotransferase (L-arginine:glycine amidinotransferase)
  • glycine amidinotransferase, mitochondrial
  • glycine amidinotransferase, mitochondrial precursor
  • L-arginine:glycine amidinotransferase
  • transamidinase

Frequently Asked Questions

Diagnosis of GATM deficiency usually involves a combination of clinical evaluation, biochemical tests to measure creatine and guanidinoacetic acid (GAA) levels in blood, urine, or cerebrospinal fluid, and genetic testing to identify mutations in the GATM gene. Magnetic resonance spectroscopy (MRS) of the brain can also show reduced creatine levels.
Yes, treatment for GATM deficiency typically involves dietary supplementation with creatine. This helps to replenish the body's creatine stores, especially in the brain, and can significantly improve neurological symptoms, developmental outcomes, and muscle strength if started early. Some individuals may also benefit from dietary restrictions to reduce precursors that can lead to accumulation of guanidinoacetic acid.
Children with GATM deficiency typically show delayed development, including delays in reaching motor milestones like sitting or walking, and intellectual disability. Muscle weakness can also be a prominent symptom. Since the brain requires a lot of energy, neurological issues are often the most severe and noticeable effects of the creatine shortage.
The long-term outlook for GATM deficiency can be significantly improved with early diagnosis and consistent treatment, primarily with creatine supplementation. Many individuals, especially those who start treatment early in life, can experience substantial improvements in developmental delays, intellectual function, and muscle weakness, leading to a better quality of life and potentially preventing severe neurological damage.
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.

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