Genome-Wide Pathway Analysis Identifies Genetic Pathways Associated with Psoriasis

Area of Science:

• Genetics
• Immunology
• Dermatology

Background:

• Psoriasis is a chronic inflammatory skin disease with complex genetic underpinnings.
• A significant portion of psoriasis heritability remains unexplained by known genetic factors.
• Common genetic variants with small effect sizes within biological pathways may contribute to this missing heritability.

Purpose of the Study:

• To identify novel genetic variations associated with psoriasis risk at the biological pathway level.
• To investigate the role of common genetic pathways in explaining psoriasis heritability.
• To uncover new biological mechanisms contributing to psoriasis susceptibility.

Main Methods:

• Genome-wide pathway analysis was conducted on 598,258 single nucleotide polymorphisms in a Spanish discovery cohort (2,281 cases/controls).
• Analysis utilized 1,053 reference biological pathways to assess genetic associations.
• Replication analysis was performed in an independent UK cohort (7,353 individuals).

Main Results:

• Fourteen genetic pathways were significantly associated with psoriasis risk in the discovery cohort.
• Six of these pathways were successfully replicated in the UK cohort.
• Novel pathways linked to psoriasis risk included retinol metabolism, inorganic ion/amino acid transport, and post-translational protein modification.
• MGAT5 demonstrated strong network centrality within the post-translational modification pathway and was further validated.

Conclusions:

• The study identified novel genetic pathways contributing to psoriasis susceptibility, offering insights into its complex genetic architecture.
• These findings suggest that common genetic variants within specific biological pathways play a crucial role in explaining missing heritability in psoriasis.
• The identified pathways, such as retinol metabolism and protein modification, represent potential new targets for understanding psoriasis pathogenesis.