To define the frequency of the R92Q tumor necrosis factor receptor-associated periodic syndrome (TRAPS) mutation in patients with familial Mediterranean fever (FMF) and to study the role of this mutation in FMF.
Ninety-two FMF patients and 250 controls were genotyped for the R92Q mutation. The frequency of R92Q was assessed among 5 groups of FMF patients.
R92Q was found in 6% of the controls, with an especially high carrier rate among Moroccan Jews (8%). R92Q was found in 3 (3.2%) of the 92 FMF patients, 1 homozygous for the MEFV M694V mutation and 2 heterozygous for M694V. All 3 patients showed partial response to colchicine. R92Q was not found in patients unresponsive to colchicine, nor was it found in patients with amyloidosis or in patients with FMF-like disease without MEFV mutations.
The frequency of the R92Q mutation in FMF patients is comparable with that of controls. Despite the fact that TRAPS and FMF share common biochemical pathways, we found no evidence for an interaction between these two genes.