title: Maternal history of autoimmune disease and later development of tourette syndrome in offspring.
abstract: OBJECTIVE
  In a nationwide prospective cohort study, we examined the possible association between maternal autoimmune disease (AD) and later diagnosis of Tourette syndrome (TS) in offspring.
  
  
  METHODS
  Data from national Danish health registers identified a cohort consisting of all children born in Denmark between 1990 and 2007 (n = 1,116,255), followed prospectively from birth until 2011, date of TS diagnosis, death, or emigration/disappearance, whichever came first. The incidence rate ratio (IRR) of TS, dependent on whether or not the mother had a prior diagnosis of AD, was estimated by Poisson regression with 95% CIs and adjusted for age, calendar time, place of birth, maternal and paternal age, parental psychiatric diagnoses other than TS, and parental TS.
  
  
  RESULTS
  The cohort contributed a total of 13,000,162 person years and 2,442 participants with a diagnosis of TS (414 females and 2,028 males). Prior maternal AD was found in 110 of the 2,442 children with TS, corresponding to an increased risk of TS, with an adjusted IRR of 1.22 (95% CI = 1.01-1.48). Maternal history of a prior AD increased the risk of TS in males, with an adjusted IRR of 1.29 (95% CI = 1.05-1.58), but not in females, with an adjusted IRR of 0.89 (95% CI = 0.52-1.52).
  
  
  CONCLUSIONS
  Maternal AD was associated with a 29% increased incidence rate of TS in male offspring. This finding supports the hypothesis that neuroimmunological disorders may act as a component in the etiology of a subset of TS.
authors.affiliation: National Centre for Register-Based Research (NCRR), Aarhus University, Aarhus, Denmark, and the Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus and Copenhagen, Denmark; Hospital of Telemark, Kragerø, Norway. Electronic address: sdalsgaard@econ.au.dk.
authors.forename: Søren
authors.initials: S
authors.lastname: Dalsgaard
authors.affiliation: National Centre for Register-Based Research (NCRR), Aarhus University, Aarhus, Denmark, and the Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus and Copenhagen, Denmark; Bioinformatics Research Centre, Aarhus University.
authors.forename: Berit L
authors.initials: BL
authors.lastname: Waltoft
authors.affiliation: Child Study Center, Yale University School of Medicine, New Haven, CT.
authors.forename: James F
authors.initials: JF
authors.lastname: Leckman
authors.affiliation: NCRR, School of Business and Social Sciences, Aarhus University, and the Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH.
authors.forename: Preben Bo
authors.initials: PB
authors.lastname: Mortensen
mesh_terms: D000293:Adolescent; D000328:Adult; D001327:Autoimmune Diseases / Q000453:epidemiology*; D002648:Child; D003718:Denmark; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D009035:Mothers; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology*; D011446:Prospective Studies; D012042:Registries; D012044:Regression Analysis; D012737:Sex Factors; D005879:Tourette Syndrome / Q000175:diagnosis / Q000209:etiology*; D055815:Young Adult
keywords: Tourette syndrome; autoimmune disease; cohort study; neuroimmunology; tics