Improved understanding of psoriasis genetics and structural variations

Linked Article: Zhen et al. Br J Dermatol 2022; 186:307–317.

Psoriasis is an immune-mediated, genetic (inherited) disease that affects the skin or joints, or both. In Europe and North America, psoriasis is found in about 2% of the population. This study is from China and it set out to study an area of psoriasis genetics relating to structural variations (SVs) that may predispose people to psoriasis (make it more likely people will develop psoriasis). SVs are types of genetic variation that contribute to diseases and include insertions, deletions, inversions and copy number variations in DNA segments. Currently not very much is known about the contribution of SVs to psoriasis susceptibility or the relationship of SVs to genetic signals we already know about.

This study included over 45,000 participants from the Chinese Han population. Fine mapping analysis (a method to identify true risk variants), genetic interaction analysis (a method to explore the relationship between two variants) and RNA expression analysis (an analysis to explore the relationship between SVs and gene expression) were conducted. Three novel SVs predisposing people to psoriasis were identified.

Further studies are needed with more participants but this study provides the most comprehensive SV ‘map’ of psoriasis so far.