The pathogenesis and genetics of psoriasis

Area of Science:

• Immunodermatology
• Genetics
• Molecular Biology

Background:

• Psoriasis vulgaris and psoriatic arthritis are complex genetic disorders.
• Previous linkage studies identified candidate loci, but robust genetic associations required advanced techniques.
• Genome-wide association studies (GWAS) have significantly advanced understanding of psoriasis genetics.

Purpose of the Study:

• To integrate findings from genetic studies into a cohesive pathogenic model of psoriatic disease.
• To identify key signaling networks and genes implicated in the pathogenesis of psoriasis and psoriatic arthritis.
• To explore the potential implications of genetic findings for disease classification, treatment, and prognosis.

Main Methods:

• Review and integration of data from linkage studies and genome-wide association studies (GWAS).
• Analysis of genetic associations within and outside the major histocompatibility complex (MHC).
• Categorization of identified genes based on their roles in distinct pathogenic pathways.

Main Results:

• Identification of numerous genes associated with psoriasis, located both inside and outside the MHC.
• Genes implicated in skin barrier function (e.g., LCE3, DEFB4, GJB2).
• Genes involved in innate immunity (NF-κB signaling: TNFAIP3, TYK2, CARD14) and adaptive immunity (IL-23/IL-17 axis: HLA-C, IL23R, ERAP1).

Conclusions:

• A comprehensive pathogenic model integrating genetic factors in psoriasis and psoriatic arthritis is proposed.
• Understanding gene networks in skin barrier, innate, and adaptive immunity is crucial.
• Further research into gene/gene and gene/environment interactions will refine diagnosis, therapy, and prognosis.