Three Japanese patients (mother and two children) with familial Mediterranean fever associated with compound heterozygosity for L110P/E148Q/M694I and an autosomal true dominant inheritance pattern.

Familial Mediterranean fever (FMF) is characterized by repeated episodes of fever, peritonitis, pleuritis, and synovitis. We describe here 3 Japanese patients (a mother and 2 children) in whom FMF was diagnosed on analysis of MEFV. A 40-year-old woman presented with fever and abdominal pain. The patient had had these symptoms on and off since childhood and consulted many hospitals. A 38-year-old man had abdominal pain and fever since the age of 30 years. A 59-year-old woman had had episodes of fever, abdominal pain, and chest pain for more than 20 years. MEFV gene analysis showed compound heterozygosity for L110P, E148Q, and M694I in all three patients. In Japanese patients with FMF, this mode of autosomal true dominant inheritance has not yet been reported. FMF is difficult to diagnose unless it is included in the differential diagnosis by physicians. We hope that our valuable experience will promote increased awareness and understanding of FMF.