Obesity is prevalent among patients with PsA and associated with higher disease activity, worse disease impact16 17 and possibly poorer response to treatment.28 Obesity represents a state of low-grade systemic inflammation, and elevated CRP has been repeatedly described across different population, across sex and age groups.29 Adipokines secreted by adipose tissue are increasingly recognised to regulate various immune responses. The gene discussed is CRP; the disease is obesity due to melanocortin 4 receptor deficiency.