Hidradenitis Suppurativa Likely Caused by Gene-Gene Interactions

Genetics play a large role in hidradenitis suppurativa (HS) susceptibility, according to a recent study published in British Journal of Dermatology.

“Our objective was to estimate the relative importance of genetic and environmental factors underlying HS susceptibility,” wrote the study authors.

Researchers joined information on zygosity with that of HS status through the Danish Twin Registry and the Danish National Patient Registry. HS cases were identified and heritability was assessed. From the registry of approximately 100,000 twins, 170 twins (from 163 pairs) were diagnosed with HS.

Results were highly indicative of gene-gene interactions. The twin pairs were monozygotic with a case-wise concordance rate of 28% and corresponding familial risk of 73 times that of the background population. Biometrical modelling suggested a heritability of 0.80 with a multilocus index of 230, noting a possibility of up to six interacting loci.

“This twin study is substantially larger, and employs a more valid phenotype than prior studies,” concluded the study authors. “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,” they continued.

Reference
Kjaersgaard Andersen R, Clemmensen SB, Larsen LA, et al. Evidence of gene-gene interaction in Hidradenitis suppurativa - A nationwide register study of Danish twins. Br J Dermatol. Published July 21, 2021. doi:10.1111/bjd.20654