This gene encodes a mitochondrial enzyme that belongs to
the amidinotransferase family. This enzyme is involved in creatine
biosynthesis, whereby it catalyzes the transfer of a guanido group
from L-arginine to glycine, resulting in guanidinoacetic acid, the
immediate precursor of creatine. Mutations in this gene cause
arginine:glycine amidinotransferase deficiency, an inborn error of
creatine synthesis characterized by mental retardation, language
impairment, and behavioral disorders.
