title: Association of vitamin D receptor gene polymorphisms with susceptibility to asthma in Tunisian children: A case control study.
abstract: BACKGROUND
  Vitamin D and its nuclear receptor (VDR) are linked to asthma in a genetic and immunologic basis. Polymorphisms in the VDR gene may alter the actions of vitamin D and then influence the development and the severity of asthma.
  
  
  OBJECTIVE
  We aimed at elucidating the genetic association of VDR gene polymorphisms with susceptibility to asthma in Tunisian children and with serum vitamin D levels.
  
  
  METHODS
  The study included 155 patients recruited from Abderrahmen MAMI hospital in Tunisia and two hundred twenty five healthy individuals matched with patients in age and sex for comparison. VDR genotypes were determined by PCR-RFLP method using endonuclease FokI, BsmI, TaqI and ApaI and vitamin D was assessed with a radioimmunoassay kit.
  
  
  RESULTS
  The distribution of genotype frequencies differed significantly between asthmatics and controls (FokI: P=0.04; BsmI: P=0.006; TaqI: P=0.006). Haplotype analyses revealed a significant association between bAt and bat haplotypes and asthma (P=0.00076, P=0.016). When patients were stratified according to atopic status and stage of severity, no significant association was detected with VDR variants. No association was found between VDR SNPs and serum 25-hydroxyvitamin D levels.
  
  
  CONCLUSIONS
  Our study shows a relation between VDR gene polymorphisms and susceptibility to asthma in children.
authors.affiliation: Université de Tunis El Manar, Faculté de médecine de Tunis, 99/08-40 homeostasis and cell dysfunction unit research, 15 Rue Djebel Lakdar 1007, Tunis Tunisia. maalmi2010@gmail.com
authors.forename: Haifa
authors.initials: H
authors.lastname: Maalmi
authors.forename: Fayçal Haj
authors.initials: FH
authors.lastname: Sassi
authors.forename: Anissa
authors.initials: A
authors.lastname: Berraies
authors.forename: Jamel
authors.initials: J
authors.lastname: Ammar
authors.forename: Kamel
authors.initials: K
authors.lastname: Hamzaoui
authors.forename: Agnes
authors.initials: A
authors.lastname: Hamzaoui
mesh_terms: D020413:3' Untranslated Regions; D000293:Adolescent; D000483:Alleles; D001249:Asthma / Q000097:blood / Q000235:genetics*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male; D011110:Polymorphism, Genetic; D020641:Polymorphism, Single Nucleotide; D018167:Receptors, Calcitriol / Q000235:genetics*; D014416:Tunisia; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood
chemical_list: D020413:3' Untranslated Regions; D018167:Receptors, Calcitriol; D014807:Vitamin D; C104450:25-hydroxyvitamin D