Priority 12 from the Psoriatic Arthritis PSP

UNCERTAINTY: To what extent is psoriatic arthritis caused or affected by internal factors such as genetics and gut health? (JLA PSP Priority 12)
Overall ranking 12
JLA question ID 0108/12
Explanatory note It is unclear if psoriatic arthritis can be caused by factors unique to that specific person, such as their genetics or gut health. These are not necessarily things that they can influence or change. We can't change the genes we are born with. This question would build the evidence to help people understand if psoriatic arthritis is hereditary. Does genetic testing play a role to determine the chance of people living with psoriatic arthritis passing it on to their children? Does the gut biome play a role in psoriatic arthritis? 
Evidence

This question has been partially addressed in the evidence base from the following systematic reviews:
Chen, 2020. Evidence that genetic analysis and functional verification studies reveal a number of susceptibility genes for PsA. However, the exact roles of many susceptibility genes in the pathophysiology of PsA are not yet clear https://pubmed.ncbi.nlm.nih.gov/32761870/
Agrawi, 2020. Evidence that epidemiology of immune-mediated inflammatory diseases among immigrants varies according to native and host countries, immigrant generation, and disease type. The rapid evolution suggests a role for non-genetic factors and gene-environment interactions. Future studies should focus on these pattern shifts, given implications of rising global burden of IMIDs and immigration https://pubmed.ncbi.nlm.nih.gov/31351784/
Wang, 2019. Evidence that Serum lipocalin-2 concentrations are higher in psoriasis/PsA patients than controls. However, more large-scale studies are warranted to explore the association between serum lipocalin-2 and the pathogenetic mechanisms of psoriasis/PsA https://pubmed.ncbi.nlm.nih.gov/31467617/
Cimenti, 2019. Some environmental factors, trauma and stress are well related to PsA pathogenesis. More recently, factors as obesity, gut dysbiosis, infections, and smoke have been taken into consideration in PsA pathogenesis. Intricate interactions between genetic predisposition, environmental triggers and innate immune system activation give rise to an autoimmune footprint in PsA pathogenesis https://pubmed.ncbi.nlm.nih.gov/31177868/
Health Research Classification System category Inflammatory and immune system
Extra information provided by this PSP
Original uncertainty examples Is psoriatic arthritis hereditary? 
Submitted by 28 uncertainties submitted 
PSP information
PSP unique ID 0108
PSP name Psoriatic Arthritis
Total number of uncertainties identified by this PSP. 46  (To see a full list of all uncertainties identified, please see the detailed spreadsheet held on the JLA website)
Date of priority setting workshop 12 July 2021