Guanine deaminase

Guanidinoacetate methyltransferase (GAMT) is an enzyme that plays a crucial role in the biosynthesis of creatine, an organic compound that provides energy to cells in the body, particularly muscle cells. This enzyme is encoded by the GAMT gene in humans.

Function

Guanidinoacetate methyltransferase catalyzes the final step in the biosynthesis of creatine from arginine and glycine. Specifically, it transfers a methyl group from S-adenosylmethionine (SAM) to guanidinoacetate to form creatine. This reaction is essential for the energy metabolism of cells, especially those in the muscle and brain.

Clinical significance

Deficiency in GAMT is a rare genetic disorder that results in a lack of creatine in the brain, leading to intellectual disability, autism, seizures, and movement disorders. This condition, known as GAMT deficiency, is inherited in an autosomal recessive manner. It is one of the few causes of intellectual disability that can be treated with dietary supplements of creatine, arginine, and glycine.

See also

• Creatine
• Guanidinoacetate
• S-adenosylmethionine
• GAMT deficiency