Arginine: glycine amidinotransferase, deficiency ..., (Arginine: glycine amidinotransferase deficiency) - Gen GATM


Deficiency of arginine-glycine amidinotransferase is a hereditary disorder that primarily affects the brain, characterized by mild to moderate mental retardation and delayed speech development. Some affected individuals develop autistic behaviors that affect communication and social interaction. These individuals may have seizures, especially when they have a fever. In addition, children with deficiency of arginine-glycine amidinotransferase have stunted growth and development of motor skills such as sitting and walking. Affected individuals may also have weak muscle tone and tend to tire easily.

This process is due to mutations in the GATM (Glycine amidinotransferase) gene, located on the long arm of chromosome 15 (15q21.1) encoding the arginine-glycine amidinotransferase enzyme. This enzyme participates in the synthesis of compound creatine from glycine, arginine and methionine amino acids. Specifically, glycine amidinotransferase arginine-controls the first stage of the process. In this step, a compound called guanidinoacetic acid is produced by transferring a guanidino group of arginine to glycine. Guanidinoacetic acid is converted to creatine in the second process step. Creatine is necessary for the body to store and use energy properly.

They have identified at least two mutations in the gene as responsible GATM arginine deficiency: glycine amidinotransferase. These mutations result encoding an arginine: glycine amidinotransferase abnormally short or interrupt coding. Mutations of genes GATM interfere with the ability of arginine-glycine amidinotransferase to participate in the synthesis of creatine, which causes a deficiency of creatine. The effects of arginine-glycine deficiency amidinotransferase are more severe in the organs and tissues that require large amounts of energy, especially the brain.

This disease is inherited in an autosomal recessive pattern, which means that both copies of the gene in every cell must have mutations for alteration is expressed. The parents of an individual with an autosomal recessive disease have a copy of the mutated gene, but usually show no signs and symptoms of the disease.

Tests in IVAMI: in IVAMI perform detection of mutations associated with deficiency of arginine: glycine amidinotransferase, by complete PCR amplification of the exons of the gene GATM, and subsequent sequencing.

Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).