Guanidinoacetate methyltransferase deficiency

Disease Overview

Guanidinoacetate methyltransferase (GAMT) deficiency is an inherited disease that affects the brain and muscles. People with this disease may begin showing symptoms from early infancy to age three. Signs and symptoms can vary but may include mild to severe intellectual disability, recurrent seizures (epilepsy), problems with speech, and involuntary movements. People with this disease may also have behavioral problems, including hyperactivity, autistic behaviors, and self-mutilation.[9974]

GAMT deficiency is caused by changes (mutations) in the GAMT gene. The disease is inherited in an autosomal recessive manner. Diagnosis of the disease may be based on finding increased levels of guanidinoacetate in the urine, and the diagnosis can be confirmed with genetic testing. Treatment for the disease aims to increase the levels of creatine in the brain through supplementation with high doses of oral creatine monohydrate.[9944]

Synonyms

• GAMT deficiency
• Cerebral creatine deficiency syndrome 2