title: Long-term follow-up and treatment in nine boys with X-linked creatine transporter defect.
abstract: The creatine transporter (CRTR) defect is a recently discovered cause of X-linked intellectual disability for which treatment options have been explored. Creatine monotherapy has not proved effective, and the effect of treatment with L-arginine is still controversial. Nine boys between 8 months and 10 years old with molecularly confirmed CRTR defect were followed with repeated (1)H-MRS and neuropsychological assessments during 4-6 years of combination treatment with creatine monohydrate, L-arginine, and glycine. Treatment did not lead to a significant increase in cerebral creatine content as observed with H(1)-MRS. After an initial improvement in locomotor and personal-social IQ subscales, no lasting clinical improvement was recorded. Additionally, we noticed an age-related decline in IQ subscales in boys affected with the CRTR defect.
authors.affiliation: Department of Clinical Genetics, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, The Netherlands. jm.vandekamp@vumc.nl
authors.forename: Jiddeke M
authors.initials: JM
authors.lastname: van de Kamp
authors.forename: Petra J W
authors.initials: PJ
authors.lastname: Pouwels
authors.forename: Femke K
authors.initials: FK
authors.lastname: Aarsen
authors.forename: Leontine W
authors.initials: LW
authors.lastname: ten Hoopen
authors.forename: Dirk L
authors.initials: DL
authors.lastname: Knol
authors.forename: Johannes B
authors.initials: JB
authors.lastname: de Klerk
authors.forename: Ireneus F
authors.initials: IF
authors.lastname: de Coo
authors.forename: Jan G M
authors.initials: JG
authors.lastname: Huijmans
authors.forename: Cornelis
authors.initials: C
authors.lastname: Jakobs
authors.forename: Marjo S
authors.initials: MS
authors.lastname: van der Knaap
authors.forename: Gajja S
authors.initials: GS
authors.lastname: Salomons
authors.forename: Grazia M S
authors.initials: GM
authors.lastname: Mancini
mesh_terms: D020157:Amino Acid Transport Disorders, Inborn / Q000235:genetics / Q000628:therapy*; D001120:Arginine / Q000378:metabolism / Q000627:therapeutic use; D001921:Brain / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D041321:Chromosomes, Human, X; D003401:Creatine / Q000627:therapeutic use; D050172:Genes, X-Linked; D005998:Glycine / Q000627:therapeutic use; D006801:Humans; D007223:Infant; D007361:Intelligence Tests; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D026901:Membrane Transport Proteins / Q000235:genetics*; D009474:Neurons / Q000378:metabolism
chemical_list: D026901:Membrane Transport Proteins; C080679:creatine transporter; D001120:Arginine; D003401:Creatine; D005998:Glycine