MEFV gene polymorphisms and TNFRSF1A mutation in patients with inflammatory myopathy with abundant macrophages.

[familial mediterranean fever]

Inflammatory myopathy with abundant macrophages (IMAM ) has recently been proposed as a new clinical condition . Although IMAM shares certain similarities with other inflammatory myopathies , the mechanisms responsible for this condition remain unknown . Patients with familial Mediterranean fever (FMF ) and tumour necrosis factor receptor-associated periodic syndrome (TRAPS ) also often develop myalgia . We therefore investigated the polymorphisms or mutations of MEFV and TNFRSF 1 A genes in patients with IMAM to identify their potential role in this condition . We analysed the clinical features of nine patients with IMAM and sequenced exons of the MEFV and TNFRSF 1 A genes . The patients with IMAM had clinical symptoms such as myalgia , muscle weakness , erythema , fever and arthralgia . Although none of the patients were diagnosed with FMF or TRAPS , seven demonstrated MEFV polymorphisms (G 304 R , R 202 R , E 148 Q , E 148 Q-L 110 P and P 369 S-R 408 Q ), and one demonstrated a TNFRSF 1 A mutation (C 43 R ). These results suggest that MEFV gene polymorphisms and TNFRSF 1 A mutation are susceptibility and modifier genes in IMAM .