Unique spectrum of MEFV mutations in Iranian Jewish FMF patients--clinical and demographic significance.

OBJECTIVES: To determine the spectrum of mutations in the Mediterranean fever gene (MEFV) of Iranian Jews with familial Mediterranean fever (FMF) and to analyse their clinical manifestations.
METHODS: FMF patients with both parents of Iranian-Jewish (IJ) extraction or with one IJ parent (IJ-other, 10 of each) were characterized for clinical manifestations, and the B30.2 (PRYSPRY) domain of their MEFV was sequenced for mutations.
RESULTS: Only one rare mutation, R653H, and one new mutation, G632S were present in the IJ group (in 2/10 patients), whereas the new, and common mutations were present in the IJ-other patients (8/10 patients). The new mutation was traced thrice to an IJ ancestor, and although carried asymptomatically by family members, it was over-represented in the patients (3/28 unrelated IJ alleles) compared non-affected IJ subjects (1/126 alleles, P = 0.03) or with non-Jewish Iranians (0/108 alleles, P = 0.001). The mutation was associated with a distinct phenotype regarding sites involved in the attack (P = 0.001), mild severity, sole expression of febrile episodes (P = 0.01) and a male bias (P = 0.01). In two 3D PRYSPRY models the G632S mutation was localized to a surface loop and close to a putative binding site.
CONCLUSIONS: Iranian Jews with FMF have a unique spectrum of mutations including a newly described mutation with a non-typical phenotype.