FMF is caused by mutations in the MEFV gene which is located on chromosome 16p13.3. p.M680I, p.M694 V, p.M694I, p.V726A on exon 10 and p.E148Q on exon 2 are the most common mutations among FMF patients and these constitute 85 % of all.
Furthermore, the statistically significant predominance of strong heterozygous mutations such as M694V and M680I in patients with hematolymphoid neoplasm; none had own and/or family history compatible with FMF, is interesting.
White-blood cell count, CRP and IL-8 levels were higher in patients with FMF than in healthy subjects (p < 0.05) and also higher in M680I carriers than in the patients with M694V allele carriers.
Haplotype analysis of 376 Familial Mediterranean Fever (FMF) patients and 100 controls from Lebanon was performed using 4 microsatellite loci to study founder effects for the five most frequent mutations within the MEFV gene (M694V, M694I, V726A, M680I and E148Q).
In this study, the frequencies of three FMF-related MEFV mutations (M694V, M680I and V726A) were investigated in FMF patients with (AA-FMF, n = 37) and without amyloidosis (non-AA-FMF, n = 35), in patients with secondary amyloidosis related to non-FMF inflammatory conditions (S-AA, n = 19) and in a non-inflammatory control group (n = 185) by molecular genetic studies using polymerase chain reaction with the ARMS (amplification refractory mutation system) method.
To our knowledge, this is the first association between FMF and the M680I mutation later complicated by nephrotic syndrome and fibrillary glomerulonephritis.