arginine:glycine amidinotransferase deficiency
Definition An autosomal recessive disorder (OMIM:612718) characterised by developmental delay/regression, mental retardation, severe disturbance of expressive and cognitive speech, and marked cerebral depletion of creatine/phosphocreatine. Most patients develop a myopathy characterised by muscle weakness and atrophy later in life.
Molecular pathology Defects of GATM, which encodes a mitochondrial enzyme involved in creatine biosynthesis, cause arginine:glycine amidinotransferase deficiency.
Synonyms AGAT deficiency, cerebral creatine deficiency syndrome 3, creatine deficiency syndrome due to AGAT deficiency, GATM deficiency