Andreas Schulze1, Margaret Bauman2, Anne Chun-Hui Tsai3, Ann Reynolds4, Wendy Roberts5, Evdokia Anagnostou5, Jessie Cameron6, Alixandra A Nozzolillo7, Shiyi Chen8, Lianna Kyriakopoulou9, Stephen W Scherer10, Alvin Loh11. 1. Genetics and Genome Biology, Peter Gilgan Center for Research and Learning, Toronto, Ontario, Canada; Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Paediatrics, University of Toronto, Ontario, Canada; andreas.schulze@sickkids.ca. 2. Lurie Center for Autism, MassGeneral Hospital, Boston, Massachusetts; Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts; 3. Colorado University Medical School, Aurora, Colorado; Molecular and Medical Genetics, Oregon Health and Sciences University, Portland, Oregon; 4. Colorado University Medical School, Aurora, Colorado; 5. Department of Paediatrics, University of Toronto, Ontario, Canada; Holland Bloorview Kids Rehabilitation, Toronto, Ontario, Canada; 6. Genetics and Genome Biology, Peter Gilgan Center for Research and Learning, Toronto, Ontario, Canada; 7. Clinical and Translational Science Center, Harvard Medical School, Boston, Massachusetts; 8. Clinical Research Services, The Hospital for Sick Children, Toronto, Ontario, Canada; 9. Department of Paediatric Laboratory Medicine, Biochemical Genetics Laboratory, The Hospital for Sick Children, Toronto, Ontario, Canada; 10. Genetics and Genome Biology, Peter Gilgan Center for Research and Learning, Toronto, Ontario, Canada; The Centre for Applied Genomics, The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Molecular Genetics and McLaughlin Centre, University of Toronto, Ontario, Canada; 11. Department of Paediatrics, University of Toronto, Ontario, Canada; Surrey Place Center, Toronto, Ontario, Canada.
Abstract
BACKGROUND AND OBJECTIVE: Creatine deficiency may play a role in the neurobiology of autism and may represent a treatable cause of autism. The goal of the study was to ascertain the prevalence of creatine deficiency syndromes (CDSs) in children with autism spectrum disorder (ASD). METHODS: In a prospective multicenter study, 443 children were investigated after a confirmed diagnosis of ASD. Random spot urine screening for creatine metabolites (creatine, guanidinoacetate, creatinine, and arginine) with liquid chromatography-tandem mass spectrometry and second-tier testing with high-performance liquid chromatography methodology was followed by recall testing in 24-hour urines and confirmatory testing by Sanger-based DNA sequencing of GAMT, GATM, and SLC6A8 genes. Additional diagnostic tests included plasma creatine metabolites and in vivo brain proton magnetic resonance spectroscopy. The creatine metabolites in spot urine in the autism group were compared with 128 healthy controls controlled for age. RESULTS: In 443 subjects with ASD investigated for CDS, we had 0 events (event: 0, 95% confidence interval 0-0.0068), therefore with 95% confidence the prevalence of CDS is <7 in 1000 children with ASD. The autism and control groups did not vary in terms of creatine metabolites (P > .0125) in urine. CONCLUSION: Our study revealed a very low prevalence of CDS in children with nonsyndromic ASD and no obvious association between creatine metabolites and autism. Unlike our study population, we expect more frequent CDS among children with severe developmental delay, speech impairment, seizures, and movement disorders in addition to impairments in social communication, restricted interests, and repetitive behaviors.
BACKGROUND AND OBJECTIVE:Creatine deficiency may play a role in the neurobiology of autism and may represent a treatable cause of autism. The goal of the study was to ascertain the prevalence of creatine deficiency syndromes (CDSs) in children with autism spectrum disorder (ASD). METHODS: In a prospective multicenter study, 443 children were investigated after a confirmed diagnosis of ASD. Random spot urine screening for creatine metabolites (creatine, guanidinoacetate, creatinine, and arginine) with liquid chromatography-tandem mass spectrometry and second-tier testing with high-performance liquid chromatography methodology was followed by recall testing in 24-hour urines and confirmatory testing by Sanger-based DNA sequencing of GAMT, GATM, and SLC6A8 genes. Additional diagnostic tests included plasma creatine metabolites and in vivo brain proton magnetic resonance spectroscopy. The creatine metabolites in spot urine in the autism group were compared with 128 healthy controls controlled for age. RESULTS: In 443 subjects with ASD investigated for CDS, we had 0 events (event: 0, 95% confidence interval 0-0.0068), therefore with 95% confidence the prevalence of CDS is <7 in 1000 children with ASD. The autism and control groups did not vary in terms of creatine metabolites (P > .0125) in urine. CONCLUSION: Our study revealed a very low prevalence of CDS in children with nonsyndromic ASD and no obvious association between creatine metabolites and autism. Unlike our study population, we expect more frequent CDS among children with severe developmental delay, speech impairment, seizures, and movement disorders in addition to impairments in social communication, restricted interests, and repetitive behaviors.