OBJECTIVES: To study the phenotype/genotype correlations
in Arab patients with familial Mediterranean fever (FMF).
PATIENTS AND METHODS: The study was performed in a 3-year
period (February 1998-February 2001). Patients were seen in the
pediatric FMF clinic of Jordan University Hospital, and the
diagnosis of FMF was made according to published criteria.
Screening for mutations was carried out by direct sequencing of
the entire coding sequence of exon 10 and its donor splice site
and by restriction endonuclease testing for mutations in exon 2.
A total of 278 patients with clinically positive FMF were
screened.
RESULTS: Of the 278 patients, 50 (18%) had 2 mutations
identified, and 76 (27%) other patients had only 1 mutation
identified. The 50 patients with 2 mutations are the subject of
this report. The M694V/M694V and the M694V/V726A and M694I/M694I
genotypes were the most common (30%, 16%, and 14%,
respectively). Three homozygous genotypes (M694V/M694V,
V726A/V726A, and M694I/M694I) and 2 compound heterozygous
genotypes (M694V/V726A and V726A/M680I) accounted for 78% of
mutations. The difference in the mean severity score (14 +/- 2)
of the M694V/M694V group and the V726A/V726A (mean severity
score, 10 +/- 3) and M694I/M6941 (mean severity score, 6 +/- 1)
groups was statistically significant (P =.003 and.0,
respectively). The difference between the M649V/M694V group and
the M694V/V726A (mean severity score, 15 +/- 2) was not
statistically significant (P = 0.31).
CONCLUSIONS: The genotypes M694V/M694V and M694V/V726A
have a severe clinical course in Arab patients with FMF, whereas
the M694I/M694I is associated with mild disease. Copyright 2002,
Elsevier Science (USA). All rights reserved.
Institution
Department of Pediatrics, Faculty of Medicine, University of
Jordan, Amman. pal@go.com.jo
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