[Periodic fever syndrome associated with mutations in the TNF type 1 receptor gene: A differential diagnosis of familial Mediterranean fever that should not be overlooked in patients of Mediterranean origin]

Tumor Necrosis Factor Type 1 Receptor Associated Periodic Syndrome (TRAPS) is a rare autosomal dominant autosomal autoinflammatory disease associated with mutations in the TNF type 1 receptor gene (TNFRSF1A). It is characterized by relatively long recurrent febrile seizures with an average duration of 7 days accompanied by arthralgia, myalgia, and usually a rash. In a patient of Mediterranean origin with recurrent fever, familial Mediterranean fever is the first diagnosis to be suspected by argument of frequency.A retrospective observational study was conducted on patients from Mediterranean origin followed for TRAPS and included in the "Juvenile Inflammatory Rheumatism" (JIR) observational cohort in the national French autoinflammatory center. The age of onset of symptoms, age of diagnosis, number of years of wandering and treatments received were collected for each index case.Nine patients from 6 families of Mediterranean origin were included. A molecular diagnosis confirmed TRAPS in all patients. The median age at diagnosis was 26 years, the mean number of years of wandering was 17 years. The diagnosis of FMF was made first in all patients. AA amyloidosis revealed TRAPS in 2 patients. Colchicine was started without any efficacy in all cases. Five patients were treated with interleukin-1 inhibitory biotherapy with 100% efficacy.In a patient of Mediterranean origin presenting with recurrent febrile abdominal pain of AA amyloidosis, the first diagnosis to be suspected is FMF. Long relapses, dominant transmission, a non-Mediterranean relative, and the ineffectiveness of colchicine should evoke TRAPS.