Heritability of psoriasis in a large twin sample

Br J Dermatol. 2013 Aug;169(2):412-6. doi: 10.1111/bjd.12375.


Background: Previous twin studies have shown greater concordance rates for psoriasis in MZ than in DZ twins, and heritability estimates between 66% and 90%. This supports a genetic influence on psoriasis, but also highlights the fact that genes are not the only explanation for the disease.

Objectives: To study the concordance of psoriasis in a population-based twin sample.

Methods: Data on psoriasis in 10 725 twin pairs, aged 20-71 years, from the Danish Twin Registry was collected via a questionnaire survey. The concordance and heritability of psoriasis were estimated.

Results: In total, 4·1% of the men and 4·2% of the women had a lifetime history of psoriasis. The proband-wise concordance for psoriasis was larger in monozygotic than in dizygotic twins, 0·33 vs. 0·17. Genetic factors explained 68% (60-75%) of the variation in the susceptibility to psoriasis, whereas the rest of the variation was explained by nonshared environmental factors.

Conclusion: The results confirm that psoriasis is a complex multifactorial disease controlled by both exogenous and endogenous factors.

Publication types

  • Twin Study

MeSH terms

  • Adult
  • Aged
  • Denmark / epidemiology
  • Female
  • Genetic Predisposition to Disease / genetics
  • Humans
  • Male
  • Middle Aged
  • Prevalence
  • Psoriasis / epidemiology
  • Psoriasis / genetics*
  • Registries
  • Risk Factors
  • Twins, Dizygotic
  • Twins, Monozygotic
  • Young Adult