Creatine deficiency syndromes

Abstract

Creatine deficiency syndromes (CDS) are a group of inborn errors of creatine synthesis and transport and include autosomal recessive arginine:glycine amidinotransferase (AGAT) and guanidinoacetate methyltransferase (GAMT) deficiencies, and deficiency of the X-linked creatine transporter (SLC6A8). In all these disorders the common clinical hallmark is mental retardation, speech delay and epilepsy. Additional frequent manifestations include failure to thrive, growth retardation, muscular hypotonia and movement disorder (mainly extrapyramidal). The common biochemical hallmark is cerebral creatine deficiency as detected by proton magnetic resonancespectroscopy (H-MRS).