title: The Roots of Autism and ADHD Twin Study in Sweden (RATSS).
abstract: Neurodevelopmental disorders affect a substantial minority of the general population. Their origins are still largely unknown, but a complex interplay of genetic and environmental factors causing disturbances of the central nervous system's maturation and a variety of higher cognitive skills is presumed. Only limited research of rather small sample size and narrow scope has been conducted in neurodevelopmental disorders using a twin-differences design. The Roots of Autism and ADHD Twin Study in Sweden (RATSS) is an ongoing project targeting monozygotic twins discordant for categorical or dimensional autistic and inattentive/hyperactive-impulsive phenotypes as well as other neurodevelopmental disorders, and typically developing twin controls. Included pairs are 9 years of age or older, and comprehensively assessed for psychopathology, medical history, neuropsychology, and dysmorphology, as well as structural, functional, and molecular brain imaging. Specimens are collected for induced pluripotent (iPS) and neuroepithelial stem cells, genetic, gut bacteria, protein-/monoamine, and electron microscopy analyses. RATSS's objective is to generate a launch pad for novel surveys to understand the complexity of genotype-environment-phenotype interactions in autism spectrum disorder and attention-deficit hyperactivity disorder (ADHD). By October 2013, RATSS had collected data from 55 twin pairs, among them 10 monozygotic pairs discordant for autism spectrum disorder, seven for ADHD, and four for other neurodevelopmental disorders. This article describes the design, recruitment, data collection, measures, collected pairs' characteristics, as well as ongoing and planned analyses in RATSS. Potential gains of the study comprise the identification of environmentally mediated biomarkers, the emergence of candidates for drug development, translational modeling, and new leads for prevention of incapacitating outcomes.
authors.affiliation: Center of Neurodevelopmental Disorders at Karolinska Institutet,Pediatric Neuropsychiatry Unit,Department of Women's and Children's Health,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Sven
authors.initials: S
authors.lastname: Bölte
authors.affiliation: Center of Neurodevelopmental Disorders at Karolinska Institutet,Pediatric Neuropsychiatry Unit,Department of Women's and Children's Health,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Willfors
authors.affiliation: Center of Neurodevelopmental Disorders at Karolinska Institutet,Pediatric Neuropsychiatry Unit,Department of Women's and Children's Health,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Steve
authors.initials: S
authors.lastname: Berggren
authors.affiliation: Center of Neurodevelopmental Disorders at Karolinska Institutet,Pediatric Neuropsychiatry Unit,Department of Women's and Children's Health,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Joakim
authors.initials: J
authors.lastname: Norberg
authors.affiliation: Center of Neurodevelopmental Disorders at Karolinska Institutet,Pediatric Neuropsychiatry Unit,Department of Women's and Children's Health,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Lina
authors.initials: L
authors.lastname: Poltrago
authors.affiliation: Center of Neurodevelopmental Disorders at Karolinska Institutet,Pediatric Neuropsychiatry Unit,Department of Women's and Children's Health,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Katell
authors.initials: K
authors.lastname: Mevel
authors.affiliation: Center of Neurodevelopmental Disorders at Karolinska Institutet,Pediatric Neuropsychiatry Unit,Department of Women's and Children's Health,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Christina
authors.initials: C
authors.lastname: Coco
authors.affiliation: Department of Clinical Neuroscience,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Fransson
authors.affiliation: Center of Neurodevelopmental Disorders at Karolinska Institutet,Pediatric Neuropsychiatry Unit,Department of Women's and Children's Health,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Borg
authors.affiliation: MRI Research Center,Neuroradiology Clinic,Karolinska University Hospital,Stockholm,Sweden.
authors.forename: Rouslan
authors.initials: R
authors.lastname: Sitnikov
authors.affiliation: Human Genetics and Cognitive Functions,Institut Pasteur,Paris,France.
authors.forename: Roberto
authors.initials: R
authors.lastname: Toro
authors.affiliation: Center of Neurodevelopmental Disorders at Karolinska Institutet,Pediatric Neuropsychiatry Unit,Department of Women's and Children's Health,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Kristiina
authors.initials: K
authors.lastname: Tammimies
authors.affiliation: Department of Clinical Genetics,Karolinska University Hospital,Stockholm,Sweden.
authors.forename: Britt-Marie
authors.initials: BM
authors.lastname: Anderlid
authors.affiliation: Department of Clinical Genetics,Karolinska University Hospital,Stockholm,Sweden.
authors.forename: Ann
authors.initials: A
authors.lastname: Nordgren
authors.affiliation: Department of Neuroscience,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Falk
authors.affiliation: Physiology and Behavior Laboratory,Swiss Federal Institute of Technology (ETH) Zurich,Switzerland.
authors.forename: Urs
authors.initials: U
authors.lastname: Meyer
authors.affiliation: Department of Biosciences and Nutrition,Karolinska Institutet,Huddinge,Sweden.
authors.forename: Juha
authors.initials: J
authors.lastname: Kere
authors.affiliation: Section of Psychiatry and Neurochemistry,Sahlgrenska Academy,Gothenburg,Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Landén
authors.affiliation: Public Health Epidemiology,Department of Public Health Sciences,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Christina
authors.initials: C
authors.lastname: Dalman
authors.affiliation: Centre for Brain and Cognitive Development,Department of Psychological Sciences,Birkbeck,University of London,London,UK.
authors.forename: Angelica
authors.initials: A
authors.lastname: Ronald
authors.affiliation: Neuroscience and Physiology,Forensic Psychiatry,University of Gothenburg,Gothenburg,Sweden.
authors.forename: Henrik
authors.initials: H
authors.lastname: Anckarsäter
authors.affiliation: Department of Medical Epidemiology and Biostatistics,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Paul
authors.initials: P
authors.lastname: Lichtenstein
mesh_terms: D000293:Adolescent; D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology* / Q000235:genetics / Q000523:psychology; D001321:Autistic Disorder / Q000453:epidemiology* / Q000235:genetics / Q000523:psychology; D002648:Child; D003071:Cognition; D004200:Diseases in Twins / Q000453:epidemiology* / Q000235:genetics / Q000523:psychology; D004777:Environment; D005260:Female; D006801:Humans; D008297:Male; D059906:Neuroimaging; D010641:Phenotype; D011569:Psychiatric Status Rating Scales; D013548:Sweden / Q000453:epidemiology; D014429:Twins, Dizygotic / Q000235:genetics / Q000523:psychology*; D014430:Twins, Monozygotic / Q000235:genetics / Q000523:psychology*; D055815:Young Adult