title: Genotype-phenotype correlation in Japanese patients with familial Mediterranean fever: differences in genotype and clinical features between Japanese and Mediterranean populations.
abstract: BACKGROUND
  Familial Mediterranean fever (FMF) is a hereditary autoinflammatory disease characterized by recurrent self-limiting fever and serositis that mainly affects Mediterranean populations. Many patients with FMF have been reported in Japan due to increasing recognition of this condition and the availability of genetic analysis for the gene responsible, MEFV. The present study was performed to elucidate the clinical characteristics of Japanese FMF patients and to examine the precise genotype-phenotype correlation in a large cohort of Japanese FMF patients.
  
  
  METHODS
  We analyzed the MEFV genotypes and clinical manifestations in 116 patients clinically diagnosed as having FMF and with at least one mutation.
  
  
  RESULTS
  The most frequent mutation in Japanese patients was E148Q (40.2%), followed by M694I (21.0%), L110P (18.8%), P369S (5.4%), and R408Q (5.4%). In contrast, common mutations seen in Mediterranean patients, such as M694V, V726A, and M680I, were not detected in this population. The clinical features with M694I were associated with more severe clinical course compared to those seen with E148Q. P369S/R408Q showed variable phenotypes with regard to both clinical manifestations and severity. Patients with M694I showed a very favorable response to colchicine therapy, while those with P369S and R408Q did not.
  
  
  CONCLUSIONS
  Clinical features and efficacy of treatment in Japanese FMF patients vary widely according to the specific MEFV gene mutation, and therefore genetic analysis should be performed for diagnosis in cases of Japanese FMF.
authors.forename: Dai
authors.initials: D
authors.lastname: Kishida
authors.forename: Akinori
authors.initials: A
authors.lastname: Nakamura
authors.forename: Masahide
authors.initials: M
authors.lastname: Yazaki
authors.forename: Ayako
authors.initials: A
authors.lastname: Tsuchiya-Suzuki
authors.forename: Masayuki
authors.initials: M
authors.lastname: Matsuda
authors.forename: Shu-ichi
authors.initials: S
authors.lastname: Ikeda
mesh_terms: D000704:Analysis of Variance; D044466:Asian People / Q000235:genetics; D003598:Cytoskeletal Proteins / Q000235:genetics*; D004252:DNA Mutational Analysis; D010505:Familial Mediterranean Fever / Q000208:ethnology / Q000235:genetics* / Q000473:pathology; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D005838:Genotype; D006801:Humans; D007564:Japan; D008297:Male; D019083:Mediterranean Region; D009154:Mutation; D010641:Phenotype; D000071198:Pyrin
chemical_list: D003598:Cytoskeletal Proteins; C000604192:MEFV protein, human; D000071198:Pyrin