title: Comorbidities in preschool children at family risk of dyslexia.
abstract: BACKGROUND
  Comorbidity among developmental disorders such as dyslexia, language impairment, attention deficit/hyperactivity disorder and developmental coordination disorder is common. This study explores comorbid weaknesses in preschool children at family risk of dyslexia with and without language impairment and considers the role that comorbidity plays in determining children's outcomes.
  
  
  METHODS
  The preschool attention, executive function and motor skills of 112 children at family risk for dyslexia, 29 of whom also met criteria for language impairment, were assessed at ages 3½ and 4½ years. The performance of these children was compared to the performance of children with language impairment and typically developing controls.
  
  
  RESULTS
  Weaknesses in attention, executive function and motor skills were associated with language impairment rather than family risk status. Individual differences in language and executive function are strongly related during the preschool period, and preschool motor skills predicted unique variance (4%) in early reading skills over and above children's language ability.
  
  
  CONCLUSIONS
  Comorbidity between developmental disorders can be observed in the preschool years: children with language impairment have significant and persistent weaknesses in motor skills and executive function compared to those without language impairment. Children's early language and motor skills are predictors of children's later reading skills.
authors.affiliation: Department of Psychology, Royal Holloway University of London, London, UK.
authors.forename: Debbie
authors.initials: D
authors.lastname: Gooch
authors.forename: Charles
authors.initials: C
authors.lastname: Hulme
authors.forename: Hannah M
authors.initials: HM
authors.lastname: Nash
authors.forename: Margaret J
authors.initials: MJ
authors.lastname: Snowling
mesh_terms: D001288:Attention / Q000502:physiology*; D002675:Child, Preschool; D015897:Comorbidity; D004410:Dyslexia / Q000453:epidemiology; D056344:Executive Function / Q000502:physiology*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007206:Individuality; D007805:Language Development Disorders / Q000453:epidemiology / Q000503:physiopathology*; D008297:Male; D009048:Motor Skills / Q000502:physiology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011932:Reading; D012306:Risk
keywords: Comorbidity; dyslexia; executive function; language disorder; motor skills