title: Seasonality of birth month of children with celiac disease differs from that in the general population and between sexes and is linked to family history and environmental factors.
abstract: BACKGROUND
  Patients with autoimmune diseases, such as type 1 diabetes mellitus, atopic dermatitis, autoimmune thyroid diseases, and multiple sclerosis have a different seasonality of month of birth (MOB) from the general population. This study was undertaken to determine the seasonality of MOB in children with celiac disease (CD), an autoimmune-mediated enteropathy.
  
  
  METHODS
  The medical records of 431 children with CD (239 girls, 192 boys) were included in the study; 138 girls and 81 boys were under the age of 24 months. Data were analyzed by the cosinor method, which, in addition to statistical significance, provides parameters of rhythms. Statistical differences between groups were also analyzed by the chi test.
  
  
  RESULTS
  Patients with CD showed different patterns from that in the general population, which peaks in September. Boys and girls with CD were found to have a different seasonality of MOB (P < 0.02). Girls whose CD was diagnosed before age 24 months (peak July-August) had a different seasonality of MOB from those whose CD was diagnosed after age 24 months (no rhythm; P < 0.005) and showed a different seasonality from boys whose CD was diagnosed above 24 months (peak July; P < 0.02). In addition, we found a different seasonality of MOB in children with a family history of CD compared with those with no family history (P < 0.001).
  
  
  CONCLUSIONS
  Girls with the diagnosis of CD and patients of both sexes with a family history of CD have a different pattern of seasonality of birth from the general population. This is suggestive of a perinatal virus infection as a plausible candidate for the primary trigger.
authors.affiliation: Schneider Children's Medical Center of Israel, Tel Aviv University, WHO Collaborating Center for the Study of Diabetes in Youth, Petah Tikva, Israel.
authors.forename: Hadas
authors.initials: H
authors.lastname: Lewy
authors.forename: Hadas
authors.initials: H
authors.lastname: Meirson
authors.forename: Zvi
authors.initials: Z
authors.lastname: Laron
mesh_terms: D017668:Age of Onset; D002446:Celiac Disease / Q000453:epidemiology / Q000209:etiology / Q000821:virology*; D016009:Chi-Square Distribution; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D007557:Israel / Q000453:epidemiology; D007743:Labor, Obstetric; D008297:Male; D011247:Pregnancy; D012621:Seasons; D014777:Virus Diseases / Q000150:complications* / Q000453:epidemiology / Q000635:transmission