title: Do genetic mutations and genotypes contribute to onychomycosis?
abstract: BACKGROUND
  The variability in susceptibility to onychomycosis for individuals exposed to the same environmental risk factors raises the possibility that there may be individuals with a genetic predisposition to dermatophyte infection.
  
  
  OBJECTIVE
  To determine whether there are genetic mutations or genotypes which contribute to onychomycosis.
  
  
  METHODS
  The PubMed database was searched for examples of immune deficiencies resulting in dermatophyte infections.
  
  
  RESULTS
  There are mutations in the innate immune receptors Dectin-1 and its adaptor protein CARD9 which result in familial mucocutaneous infections. There are also specific human leukocyte antigen genotypes that are more common in individuals and families with a high prevalence of onychomycosis. In addition, some patients have been reported with insufficient levels of CD4+CD25+ regulatory T cells. These deficits impair a full innate and adaptive immune response and may result in chronic or recurrent infections.
  
  
  CONCLUSIONS
  There are documented mutations and genotypes that contribute to familial and individual susceptibility to onychomycosis.
authors.affiliation: Division of Dermatology, Department of Medicine, University of Toronto, Toronto, Ont., Canada.
authors.forename: Aditya K
authors.initials: AK
authors.lastname: Gupta
authors.forename: Fiona C
authors.initials: FC
authors.lastname: Simpson
authors.forename: William C
authors.initials: WC
authors.lastname: Brintnell
mesh_terms: D056704:Adaptive Immunity; D053468:CARD Signaling Adaptor Proteins / Q000235:genetics*; D016208:Databases, Factual; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology*; D005838:Genotype; D006801:Humans; D007113:Immunity, Innate / Q000502:physiology; D015994:Incidence; D037181:Lectins, C-Type / Q000235:genetics*; D008297:Male; D009154:Mutation; D014009:Onychomycosis / Q000453:epidemiology / Q000235:genetics* / Q000276:immunology; D011379:Prognosis; D000099181:Dectin-1
chemical_list: D053468:CARD Signaling Adaptor Proteins; D037181:Lectins, C-Type; D000099181:Dectin-1; C505855:CARD9 protein, human