title: Association between filaggrin null mutations and concomitant atopic dermatitis and contact allergy.
abstract: BACKGROUND
  The phenotypic traits of people with the filaggrin mutation (FLG) genotype and atopic dermatitis (AD) are still under elucidation, and the association with concomitant AD and contact allergy (CA) has not previously been examined.
  
  
  OBJECTIVE
  To assess FLG status in a subset of patients with AD and a minimum of one positive patch-test reaction.
  
  
  METHODS
  In total, 430 people from a hospital population and 3335 people from the general population were tested for FLG mutations by DNA hybridization to paramagnetic polystyrene beads and analysis on a multiplex analysis system. All of the individuals in the hospital population had a minimum of one CA. AD was diagnosed according to the UK Working Party Criteria, (questions-only version). Individuals from the hospital population who had both AD and CA were considered as cases, and comparison of mutation carrier frequency was estimated (χ(2) test) against individuals without AD but with CA from the hospital population, individuals from the general population, and individuals with AD from the general population.
  
  
  RESULTS
  The mutation frequency in patients with AD and CA in the hospital population was significantly less than that of people with AD from the general population (OR = 0.54; 95% CI 0.30-0.98). No difference in mutation frequency was found between individuals with and without AD in the hospital population (OR = 1.40; 95% CI 0.70-2.79), or between individuals with AD and CA in the hospital population and in the overall general population (OR = 1.29; 95% CI 0.76-2.20).
  
  
  CONCLUSIONS
  The spectrum of observable traits characteristic for the FLG mutation genotype in patients with AD is at present not defined. Our results indicate that the subset of patients with both AD and CA represent a phenotype of AD that is not associated with FLG mutations.
authors: National Allergy Research Centre, Department of Dermato-Allergology, Copenhagen University Hospital Gentofte, Hellerup, Denmark. bccarlsen@dadlnet.dk
authors: B C
authors: BC
authors: Carlsen
authors: J P
authors: JP
authors: Thyssen
authors: T
authors: T
authors: Menné
authors: M
authors: M
authors: Meldgaard
authors: A
authors: A
authors: Linneberg
authors: N H
authors: NH
authors: Nielsen
authors: P B
authors: PB
authors: Szecsi
authors: S
authors: S
authors: Stender
authors: J D
authors: JD
authors: Johansen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D017449:Dermatitis, Allergic Contact / Q000235:genetics*; D003876:Dermatitis, Atopic / Q000235:genetics*; D005260:Female; D000091344:Filaggrin Proteins; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007381:Intermediate Filament Proteins / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010328:Patch Tests / Q000379:methods; D010641:Phenotype; D055815:Young Adult
chemical_list: C000717249:FLG protein, human; D000091344:Filaggrin Proteins; D007381:Intermediate Filament Proteins