title: Screening for X-linked creatine transporter (SLC6A8) deficiency via simultaneous determination of urinary creatine to creatinine ratio by tandem mass-spectrometry.
abstract: High urinary creatine to creatinine ratio (U-CrCrtR) is a potential diagnostic marker of X-linked creatine transporter (SLC6A8) deficiency. We developed a tandem mass-spectrometry method to simultaneously determine urinary creatine and creatinine in 975 individuals (0-18 years). U-CrCrtR increased up to 8 years and decreased thereafter. U-CrCrtR was 2.29 and 2.12 (99th percentile: 1.87) in two males with subsequently confirmed SLC6A8 mutations. The frequency of SLC6A8 deficiency was 2.3% in 157 males at risk.
authors.affiliation: Department of Pediatrics, Division of Biochemical Diseases, British Columbia Children's Hospital, University of British Columbia, 4480 Oak Street, Vancouver, BC, Canada V6H 3V4.
authors.forename: Saadet
authors.initials: S
authors.lastname: Mercimek-Mahmutoglu
authors.forename: Adolf
authors.initials: A
authors.lastname: Muehl
authors.forename: Gajja S
authors.initials: GS
authors.lastname: Salomons
authors.forename: Birgit
authors.initials: B
authors.lastname: Neophytou
authors.forename: Dorothea
authors.initials: D
authors.lastname: Moeslinger
authors.forename: Eduard
authors.initials: E
authors.lastname: Struys
authors.forename: Olaf A
authors.initials: OA
authors.lastname: Bodamer
authors.forename: Cornelis
authors.initials: C
authors.lastname: Jakobs
authors.forename: Sylvia
authors.initials: S
authors.lastname: Stockler-Ipsiroglu
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D000375:Aging / Q000652:urine; D002648:Child; D002675:Child, Preschool; D003401:Creatine / Q000652:urine*; D003404:Creatinine / Q000652:urine*; D005260:Female; D050172:Genes, X-Linked; D005820:Genetic Testing; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D026901:Membrane Transport Proteins / Q000172:deficiency* / Q000235:genetics*; D053719:Tandem Mass Spectrometry
chemical_list: D026901:Membrane Transport Proteins; C080679:creatine transporter; D003404:Creatinine; D003401:Creatine