title: 1H MR spectroscopy as a diagnostic tool for cerebral creatine deficiency.
abstract: OBJECTIVE
  Total creatine (tCr) constitutes one of the most prominent signals in human brain MR spectra. A significant decrease in the tCr signal indicates a severe disorder of creatine metabolism. We describe the potential of 1H MR spectroscopy in differential diagnosis of creatine transporter (SLC6A8) deficiency syndrome.
  
  
  METHODS
  Two siblings, a 7-year-old female presenting with mild psychomotor delay, and a 5-year-old male with severe psychomotor retardation, epilepsy and autistic spectrum of problems including speech delay, underwent MR examination because of suspected creatine deficiency. After the MRI examination, 1H MR spectroscopy using the CSI technique was performed.
  
  
  RESULTS
  Metabolic images of N-acetylaspartate, tCr and choline concentrations showed a very low tCr signal in the male, which was approximately three times lower than in his sister (male/female/controls: tCr=1.6/4.6/7.5 mM). Despite creatine supplementation, no improvement in clinical status and tCr concentration in the MR spectra of the male was observed and diagnosis of SLC6A8 deficiency was proposed. Sequence analysis of the SLC6A8 gene revealed a novel pathogenic frameshift mutation c.219delC; p.Asn74ThrfsX23, hemizygous in the male and heterozygous in the female.
  
  
  CONCLUSIONS
  The diagnosis of X-linked mental retardation caused by the SLC6A8 deficiency can be independently established by 1H MR spectroscopy.
authors: MR-Unit, Department of Diagnostic and Interventional Radiology, Institute for Clinical and Experimental Medicine, Videnska 1958/9, 140 21, Prague 4, Czech Republic. mode@medicon.cz
authors: Monika
authors: M
authors: Dezortova
authors: Filip
authors: F
authors: Jiru
authors: Jan
authors: J
authors: Petrasek
authors: Vera
authors: V
authors: Malinova
authors: Jiri
authors: J
authors: Zeman
authors: Milan
authors: M
authors: Jirsa
authors: Milan
authors: M
authors: Hajek
mesh_terms: D001483:Base Sequence; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D003401:Creatine / Q000172:deficiency*; D017931:DNA Primers / Q000235:genetics; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D038901:X-Linked Intellectual Disability / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000172:deficiency / Q000235:genetics; D050480:Plasma Membrane Neurotransmitter Transport Proteins / Q000172:deficiency / Q000235:genetics
chemical_list: D017931:DNA Primers; D009419:Nerve Tissue Proteins; D050480:Plasma Membrane Neurotransmitter Transport Proteins; C094770:SLC6A8 protein, human; D003401:Creatine