Disease	Score

Substances	Interaction	Organism	Category

Substances	Interaction	Organism	Category

     guanidinoacetate methyltransferase deficiency At least 49 mutations in the GAMT gene cause guanidinoacetate methyltransferase deficiency, a disorder that involves intellectual disability and seizures. Most affected individuals of Portuguese ancestry have a particular mutation in which the amino acid tryptophan is replaced by the amino acid serine at position 20 in the enzyme (written as Trp20Ser or W20S). GAMT gene mutations impair the ability of the guanidinoacetate methyltransferase enzyme to participate in creatine synthesis, resulting in a shortage of creatine. The effects of guanidinoacetate methyltransferase deficiency are most severe in organs and tissues that require large amounts of energy, especially the brain.

     The GAMT gene provides instructions for making the enzyme guanidinoacetate methyltransferase, which is active (expressed) mainly in the liver. 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, guanidinoacetate methyltransferase controls the second step of this process. In this step, creatine is produced from another compound called guanidinoacetate. Creatine is needed for the body to store and use energy properly. It is involved in providing energy for muscle contraction, and is also important in nervous system functioning. In addition to its role in creatine synthesis, the guanidinoacetate methyltransferase enzyme is thought to help activate a process called fatty acid oxidation. This process provides an energy source for cells during times of stress when their normal fuel, the simple sugar glucose, is scarce.

Condition	Change (log2fold)	Comparison	Species	Experimental variables	Experiment name

Condition	Change (log2fold)	Comparison	Species	Experimental variables	Experiment name

The following transcription factors affect gene expression:

• CUTL1
• Pax-6
• E2F-1
• E2F-4
• E2F-5
• YY1
• Nkx5-1

Tissue specificity:

Expressed in liver.

Molecular Function:

• Guanidinoacetate N-Methyltransferase Activity
• Methyltransferase Activity

Biological Processes:

• Animal Organ Morphogenesis
• Creatine Biosynthetic Process
• Creatine Metabolic Process
• Muscle Contraction
• Regulation Of Multicellular Organism Growth
• S-Adenosylhomocysteine Metabolic Process
• S-Adenosylmethionine Metabolic Process
• Spermatogenesis
• Embryonic Liver Development

Drug Bank:

• Creatine
• Guanidine

*synonyms