Clinical and genetic features of familial Mediterranean fever in Japan.
OBJECTIVE
Familial Mediterranean fever (FMF) is thought to be a rare disorder in Japan, and the clinical features of Japanese patients with FMF remain unclear. Our aim was to elucidate the clinical characteristics of FMF in Japanese patients.


METHODS
We analyzed clinical and genetic data of 80 patients based on the results of a nationwide questionnaire survey and review of the literature.


RESULTS
From clinical findings of 80 Japanese patients, high-grade fever was observed in 98.8%, chest attacks (pleuritis symptoms) in 61.2%, abdominal attacks (peritonitis symptoms) in 55.0%, and arthritis in 27.5%. Twenty-four percent of patients experienced their first attacks before 10 years of age, 40% in their teens, and 36% after age 20 years. Colchicine was effective in many patients at a relatively low dose (< 1.0 mg/day). AA amyloidosis was seen in only 1 patient. Common MEFV mutation patterns were E148Q/M694I (25.0%), M694I alone (17.5%), and L110P/E148Q/M694I (17.5%), and no patient carried the M694V mutation, the most common mutation in Mediterranean patients with FMF.


CONCLUSIONS
A larger than expected number of patients with FMF exist in Japan, and the clinical presentation of Japanese FMF patients seems to be relatively milder than those of Mediterranean FMF patients. AA amyloidosis rarely occurs in Japanese patients, probably due to difference in patterns of the MEFV genotype between Japanese and Mediterranean patients.
Tsuchiya-Suzuki
Ayako
A
Departments of Medicine (Neurology and Rheumatology) andPediatrics, Shinshu University School of Medicine, Matsumoto; and theNational Center of Neurology and Psychiatry, Tokyo, Japan.
Yazaki
Masahide
M
Nakamura
Akinori
A
Yamazaki
Kazuko
K
Agematsu
Kazunaga
K
Matsuda
Masayuki
M
Ikeda
Shu-Ichi
S
D000293:Adolescent; D000328:Adult; D000686:Amyloidosis / Q000208:ethnology / Q000235:genetics / Q000503:physiopathology; D044466:Asian People / Q000235:genetics* / Q000706:statistics & numerical data*; D003598:Cytoskeletal Proteins / Q000235:genetics*; D003625:Data Collection; D010505:Familial Mediterranean Fever / Q000208:ethnology* / Q000235:genetics* / Q000503:physiopathology; D005260:Female; D005838:Genotype; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D000071198:Pyrin; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D055815:Young Adult
D003598:Cytoskeletal Proteins; C000604192:MEFV protein, human; D000071198:Pyrin