title: Etiology of congenital hypothyroidism in Isfahan: Does it different?
abstract: BACKGROUND
  Considering the higher prevalence of congenital hypothyroidism (CH) in Iran and the importance of determination of the etiology of CH for assessing appropriate treatment strategies, understanding the pathogenesis of CH and the implications of its inheritance and prognosis, the aim of this study was to determine the etiology of CH 7 years after initiation of the program in Isfahan province.
  
  
  METHODS
  In this cross-sectional study, children with a primary diagnosis of CH studied. They clinically examined and their medical files were reviewed by a Pediatric Endocrinologist. Considering screening and follow-up lab data and radiologic findings the etiology of CH was determined. Screening properties of different etiologies of CH was compared.
  
  
  RESULTS
  In this study, 437 patients with permanent CH (PCH) were studied. Etiology of PCH in 316 (72.3%) and 121 (27.7%) of cases was thyroid dyshormonogenesis and thyroid dysgenesis, respectively. Prevalence of agenesis, ectopia, hypoplasia and hemiagenesis in thyroid dysgenetic patients was 13.3%, 6.4%, 4.3% and 3.7% respectively. Mean of thyroid stimulating hormone in screening, recall and after discontinuing treatment at 3 years of age was significantly lower in dyshormonogenetic CH patients than dysgenetic ones(P < 0.01).
  
  
  CONCLUSIONS
  Seven years of our experiences in CH screening program indicated that the etiology of CH in Isfahan, with a higher rate of CH, with a predominance of thyroid dyshormonogenesis is different from most of the studies world-wide and similar to other reports from Iran. The findings of the current study provide us baseline information for determination of CH pathogenesis in this region.
authors.affiliation: Department of Pediatrics, Isfahan University of Medical Sciences, Isfahan, Iran ; Isfahan Endocrine and Metabolism Research Center, Isfahan University of Medical Sciences, Isfahan, Iran ; Child Growth and Development Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mahin
authors.initials: M
authors.lastname: Hashemipour
authors.affiliation: Department of Pediatrics, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Ghasemi
authors.affiliation: Child Growth and Development Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Silva
authors.initials: S
authors.lastname: Hovsepian
authors.affiliation: Isfahan Health Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Kamal
authors.initials: K
authors.lastname: Heiydari
authors.affiliation: Isfahan Health Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Sajadi
authors.affiliation: Isfahan Health Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Rezvaneh
authors.initials: R
authors.lastname: Hadian
authors.affiliation: Department of Biostatistics and Epidemiology, Health School, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Marjan
authors.initials: M
authors.lastname: Mansourian
authors.affiliation: Isfahan Endocrine and Metabolism Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Naghme
authors.initials: N
authors.lastname: Mirshahzadeh
authors.affiliation: Child Growth and Development Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Roya
authors.initials: R
authors.lastname: Kelishadi
authors.affiliation: Isfahan Health Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Marzie
authors.initials: M
authors.lastname: Dalvi
keywords: Congenital hypothyroidism; dysgenesis; dyshormonogenesis; permanent