title: Analysis of FOXP3 gene in children with allergy and autoimmune diseases.
abstract: BACKGROUND
  Allergy and autoimmunity are important immunological entities underlying chronic diseases in children. In some cases both entities develop simultaneously in the same patient. FOXP3 gene codes for a transcription factor involved in regulation of the immune system. Considering that regulatory T cells are involved in controlling immunological disease development, and the relevant role of FOXP3 in this kind of T cells, the objective of this study was to analyse the FOXP3 gene in the most prevalent autoimmune diseases and/or allergies in childhood in a European population.
  
  
  METHODS
  A total of 255 Caucasian individuals, 95 controls and 160 patients diagnosed with allergic, autoimmune or both diseases were included in this study. The molecular analysis of FOXP3 was performed by DNA sequencing following the recommendations for quality of the European Molecular Genetics Quality Network. Genomic DNA was extracted from peripheral blood of all participants and was amplified using the polymerase chain reaction. After the visualisation of the amplified fragments by agarose gel-electrophoresis, they were sequenced.
  
  
  RESULTS
  Thirteen different polymorphisms in FOXP3 gene were found, seven of which had not been previously described. The mutated allele of SNP 7340C>T was observed more frequently in the group of male children suffering from both allergic and autoimmune diseases simultaneously (p=0.004, OR=16.2 [1.34-195.15]).
  
  
  CONCLUSIONS
  In this study we identified for first time genetic variants of FOXP3 that are significantly more frequent in children who share allergic and autoimmune diseases. These variants mainly affect regulatory sequences that could alter the expression levels of FOXP3 modifying its function including its role in Treg cells.
authors.affiliation: Department of Paediatrics, Clinic Hospital Virgen de la Arrixaca, Murcia, Spain.
authors.forename: R M
authors.initials: RM
authors.lastname: Pacheco-Gonzalez
authors.affiliation: Department of Statistics, University of Salamanca, Salamanca, Spain; Biosanitary Institute of Salamanca IBSAL, Salamanca, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Avila
authors.affiliation: Biosanitary Institute of Salamanca IBSAL, Salamanca, Spain; Department of Allergy, University Hospital of Salamanca, Salamanca, Spain. Electronic address: idg@usal.es.
authors.forename: I
authors.initials: I
authors.lastname: Dávila
authors.affiliation: Biosanitary Institute of Salamanca IBSAL, Salamanca, Spain.
authors.forename: A
authors.initials: A
authors.lastname: García-Sánchez
authors.affiliation: Biosanitary Institute of Salamanca IBSAL, Salamanca, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Hernández-Hernández
authors.affiliation: Biosanitary Institute of Salamanca IBSAL, Salamanca, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Benito-Pescador
authors.affiliation: Department of Paediatrics, University Hospital of Salamanca, Salamanca, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Torres
authors.affiliation: Biosanitary Institute of Salamanca IBSAL, Salamanca, Spain; Department of Paediatrics, University Hospital of Salamanca, Salamanca, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Prieto-Matos
authors.affiliation: Biosanitary Institute of Salamanca IBSAL, Salamanca, Spain; Department of Clinical Biochemistry, University Hospital of Salamanca, Salamanca, Spain; Department of Medicine, University of Salamanca, Salamanca, Spain. Electronic address: misidoro@usal.es.
authors.forename: M
authors.initials: M
authors.lastname: Isidoro-Garcia
authors.affiliation: Biosanitary Institute of Salamanca IBSAL, Salamanca, Spain; Department of Paediatrics, University Hospital of Salamanca, Salamanca, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Lorente
authors.affiliation: Biosanitary Institute of Salamanca IBSAL, Salamanca, Spain; Department of Microbiology and Genetics, University of Salamanca, Salamanca, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Sanz
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D001327:Autoimmune Diseases / Q000276:immunology*; D004252:DNA Mutational Analysis; D005260:Female; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism*; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D013030:Spain; D050378:T-Lymphocytes, Regulatory / Q000502:physiology*; D044465:White People
chemical_list: C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors
keywords: Allergy; Asthma; Atopy; Autoimmunity; FOXP3; Gene; IPEX; Paediatrics; Polymorphisms; Treg