Creatine transporter deficiency in two adult patients with static encephalopathy

J Inherit Metab Dis. 2009 Dec:32 Suppl 1:S91-6. doi: 10.1007/s10545-009-1083-2. Epub 2009 Mar 25.


Creatine transporter deficiency is a recently identified X-linked inborn error of metabolism. The natural course of the disease is not well delineated since clinical data from adult patients have scarcely been reported. A progressive course of the disease has been noted in a few described cases. We report the first two Spanish adult patients with creatine transporter deficiency and compare their clinical phenotype and the evolution of the disease with those of other published cases. The two brothers were identified in a study of a cohort of 610 mentally handicapped male patients. The disease was detected by biochemical studies and confirmed by DNA studies. The most significant clinical features were mental retardation, epilepsy and autistic behaviour, and these symptoms did not worsen, in contrast to other reports. They did not present gastrointestinal problems or movement disorders. Creatine transporter deficiency could be an underdiagnosed metabolic disorder and should be considered in adult patients with mental retardation. Clinical presentation of this disorder showed marked differences among adult patients and the course of the disease was static in our cases. Detection of additional adult patients might allow better understanding of the phenotypic outcome at a later age.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Adult
  • Aged
  • Amino Acid Transport Disorders, Inborn / genetics*
  • Amino Acid Transport Disorders, Inborn / metabolism*
  • Autistic Disorder / genetics
  • Autistic Disorder / metabolism
  • Brain Diseases / genetics*
  • Brain Diseases / metabolism*
  • Consanguinity
  • Epilepsy / genetics
  • Epilepsy / metabolism
  • Female
  • Genetic Diseases, X-Linked / genetics
  • Genetic Diseases, X-Linked / metabolism
  • Humans
  • Male
  • Mental Retardation, X-Linked / genetics
  • Mental Retardation, X-Linked / metabolism
  • Mutation
  • Nerve Tissue Proteins / deficiency*
  • Nerve Tissue Proteins / genetics*
  • Pedigree
  • Phenotype
  • Plasma Membrane Neurotransmitter Transport Proteins / deficiency*
  • Plasma Membrane Neurotransmitter Transport Proteins / genetics*


  • Nerve Tissue Proteins
  • Plasma Membrane Neurotransmitter Transport Proteins
  • SLC6A8 protein, human