Evidence of gene-gene interaction in hidradenitis suppurativa: a nationwide registry study of Danish twins

R Kjaersgaard Andersen*, S B Clemmensen, Lisbeth Aagaard Larsen, J V B Hjelmborg, N Ødum, G B E Jemec, K Christensen


Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

82 Downloads (Pure)


Background: Hidradenitis suppurativa (HS) is a recurrent inflammatory skin disease that, apart from rare causative loss-of-function mutations, has a widely unknown genetic aetiology. Our objective was to estimate the relative importance of genetic and environmental factors underlying HS susceptibility.

Methods: Through the Danish Twin Registry and the Danish National Patient Registry we joined information on zygosity with that of HS status. HS cases were identified by International Code of Diseases 8 (705.91) and 10 (L73.2). Heritability was assessed by the classic biometric model and the possibility of gene-gene interaction through the multi-locus modeling approach.

Results: Amongst 100,044 registered twins, we found 170 twins (from 163 pairs) diagnosed with HS. The seven concordant pairs were all monozygotic, and monozygotic twins had a casewise concordance rate of 28% (95% CI: 7%; 49%), corresponding to a familial risk of 73 (95% CI 13; 133) times that of the background population.

The biometrical modelling suggested a heritability of 0.80 (95% CI 0.67; 0.93), and the multilocus index estimate was 230 (95% CI: 60; 400). This is highly indicative of gene-gene interactions, with the possibility of up to six interacting loci.

Conclusion: This twin study is substantially larger, and employs a more valid phenotype than prior studies. Genetics account for the majority of the HS susceptibility, and HS is most likely caused by gene-gene interactions rather than monogenetic mutations or solely additive genetic factors. New approaches aimed at assessing potential interactions at a SNP-SNP level should be implemented in future HS genome-wide association studies.
TidsskriftBritish Journal of Dermatology
Udgave nummer1
Sider (fra-til)78-85
StatusUdgivet - jan. 2022

Bibliografisk note

This article is protected by copyright. All rights reserved.


Dyk ned i forskningsemnerne om 'Evidence of gene-gene interaction in hidradenitis suppurativa: a nationwide registry study of Danish twins'. Sammen danner de et unikt fingeraftryk.