Patients with a sure FMF phenotype had a higher frequency of MEFV exon 10 mutation (M694I) and a lower frequency of MEFV exon 3 mutations (P369S, R408Q) compared with those with a probable FMF phenotype.
P369S/R408Q substitutions are associated with a highly variable phenotype, and are infrequently associated with typical FMF symptoms, however a trial of colchicine is warranted in all.
P369S/R408Q substitutions are associated with a highly variable phenotype, and are infrequently associated with typical FMF symptoms, however a trial of colchicine is warranted in all.
Two of the patients (siblings with definite FMF) were heterozygous for both E148Q and M694I, and the remaining patient (with probable FMF and no family history of the disease) was heterozygous for both P369S and R408Q.
Eight mutations, one of which (R408Q) is new, were found to account for 93% of the 163 independent FMF alleles, with both FMF alleles identified in 89% of the patients.