title: Gene Polymorphism of Interleukin-4, Interleukin-4 Receptor and STAT6 in Children with Atopic Dermatitis in Taif, Saudi Arabia.
abstract: OBJECTIVE
  This work was performed to evaluate the level of IL-4, and to clarify the role of IL-4 gene polymorphism at position cytosine -590-to-thyamine (C-590T), IL-4Rα gene polymorphism at position adenine +4679-to-guanine (A+4679G) [isoleucine-50-valine (I50V)] and STAT6 gene polymorphism at position guanine 2964-to-adenine (G2964A) in Saudi children with non-atopic dermatitis (non-AD) and atopic dermatitis (AD) to identify their role in the pathogenesis of these diseases.
  
  
  METHODS
  This study included 150 children: 50 healthy children as controls, 50 with non-AD, and 50 with AD. They were subjected to full clinical examination, complete blood picture, skin prick test, and determination of serum interleukin-4 (IL-4) and total immunoglobulin-E (IgE) levels. Detection of interleukin-4 gene (C-590T), interleukin-4 receptor alpha gene (A+4679G) (I50V), and STAT6 gene (G2964A) polymorphisms were performed by PCR-based restriction fragment length polymorphism (PCR-RFLP).
  
  
  RESULTS
  There was a significant (P < 0.01) association between genotype and allele frequencies of IL-4Rα (A+4679G) (I50V) polymorphism in the AD group (but not non-AD group). Moreover, there was a significant association between genotype and allele frequencies of the STAT6 (G2946A) polymorphism in the non-AD (P < 0.05) and AD (P < 0.01) groups. On the other hand, there was no significant association between genotype and allele frequencies of the (C-590T) polymorphism in the non-AD group and AD group. There was a significant (P < 0.001) higher total IgE level in patients compared to the controls. Moreover, the mean values of total IgE were significantly different among the different allelic variants of (C-590T), (I50V), (G2964A) polymorphisms of IL-4, IL-4Rα, and STAT6 genes, respectively, in all the studied groups. On the other hand, there was no significant difference of serum IL-4 levels among all the studied patients, or among the different allelic variants of (C-590T), (I50V), (G2964A) polymorphisms of IL-4, IL-4Rα, and STAT6 genes, respectively.
  
  
  CONCLUSIONS
  IL-4Rα gene (I50V) and STAT6 gene (G2964) polymorphisms may play a role in development of eczema; however, the IL-4 gene polymorphism (C-590T) had no relationship with susceptibility to the disease among Saudi children.
authors.affiliation: a Medical Laboratories Department, Faculty of Applied Medical Sciences , Taif University , Taif , Saudi Arabia.|b Medical Biochemistry Department, Faculty of Medicine , Zagazig University , Zagazig , Egypt.
authors.forename: Yousri M
authors.initials: YM
authors.lastname: Hussein
authors.affiliation: c Community Medicine Department, Faculty of Medicine , Taif University , Taif , Saudi Arabia.
authors.forename: Saad S
authors.initials: SS
authors.lastname: Alzahrani
authors.affiliation: d Pediatric Department, Faculty of Medicine , Taif University , Taif , Saudi Arabia.
authors.forename: Abd Allah
authors.initials: AA
authors.lastname: Alharthi
authors.affiliation: a Medical Laboratories Department, Faculty of Applied Medical Sciences , Taif University , Taif , Saudi Arabia.
authors.forename: Ayman S
authors.initials: AS
authors.lastname: Alhazmi
authors.affiliation: a Medical Laboratories Department, Faculty of Applied Medical Sciences , Taif University , Taif , Saudi Arabia.|e Medical Microbiology and Immunology Department, Faculty of Medicine , Menoufiya University , Menoufiya , Egypt.
authors.forename: Mabrouk M
authors.initials: MM
authors.lastname: Ghonaim
authors.affiliation: f Community Medicine, Faculty of Applied Medical Sciences , Taif University , Taif , Saudi Arabia.
authors.forename: Abd Alrahman N
authors.initials: AA
authors.lastname: Alghamdy
authors.affiliation: a Medical Laboratories Department, Faculty of Applied Medical Sciences , Taif University , Taif , Saudi Arabia.|g Medical Biochemistry Department, Damietta Faculty of Medicine , Al-Azhar University , Damietta , Egypt.
authors.forename: Ahmad
authors.initials: A
authors.lastname: El Askary
mesh_terms: D000483:Alleles; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003876:Dermatitis, Atopic / Q000235:genetics* / Q000276:immunology; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D015847:Interleukin-4 / Q000097:blood / Q000235:genetics*; D008297:Male; D020641:Polymorphism, Single Nucleotide; D019948:Receptors, Interleukin-4 / Q000235:genetics*; D050800:STAT6 Transcription Factor / Q000235:genetics*; D012529:Saudi Arabia
chemical_list: D019948:Receptors, Interleukin-4; D050800:STAT6 Transcription Factor; D015847:Interleukin-4; D007073:Immunoglobulin E
keywords: IL-4Rα; STAT6; interleukin-4 (IL-4); single nucleotide polymorphism (SNP) atopic dermatitis (AD)