guanidinoacetate methyltransferase deficiency

A cerebral creatine deficiency syndrome that is characterized by severe intellectual disability, seizures, speech problems and involuntary movements, has_material_basis_in homozygous or compound heterozygous mutation in the GAMT gene on chromosome 19p13.

Signs and symptoms

• Hypotonia
• Severe intellectual disability
• Elevated circulating guanidinoacetic acid concentration
• Elevated brain guanidinoacetate level by MRS
• Delayed speech and language development
• Reduced tissue guanidinoacetate methyltransferase activity
• Severe global developmental delay
• Decreased serum creatinine
• Hypertonia
• Seizure

Also known as: Cerebral creatine deficiency syndrome 2; GAMT deficiency