Funding sources None.
Heritability of psoriasis in a large twin sample
Article first published online: 13 AUG 2013
© 2013 The Authors BJD © 2013 British Association of Dermatologists
British Journal of Dermatology
Volume 169, Issue 2, pages 412–416, August 2013
How to Cite
Lønnberg, A.S., Skov, L., Skytthe, A., Kyvik, K.O., Pedersen, O.B. and Thomsen, S.F. (2013), Heritability of psoriasis in a large twin sample. British Journal of Dermatology, 169: 412–416. doi: 10.1111/bjd.12375
Conflicts of interest None declared.
- Issue published online: 13 AUG 2013
- Article first published online: 13 AUG 2013
- Accepted manuscript online: 9 APR 2013 01:51PM EST
- Manuscript Accepted: 26 MAR 2013
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.
To study the concordance of psoriasis in a population-based twin sample.
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.
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.
The results confirm that psoriasis is a complex multifactorial disease controlled by both exogenous and endogenous factors.