Mutations in the familial Mediterranean fever gene of patients with IgA nephropathy and other forms of glomerulonephritis.

Glomerulonephritis, particularly IgA nephropathy (IgAN), seems to be more common in familial Mediterranean fever (FMF), an inherited disease caused by mutations in the MEditerranean FeVer gene (MEFV). The present study is aimed to determine, in populations not suffering from FMF, whether carriage of MEFV mutations may modify or precipitate IgAN and other forms of primary glomerulonephritis (PGN). Forty patients with biopsy proven IgAN and 40 with PGN were surveyed for the presence of the three most common MEFV mutations (M694V, V726A and E148Q), using polymerase chain reaction amplification and restriction enzyme analysis. The rate of MEFV mutations in the patients was related to the expected carrier rate in the general population of the same ethnic extraction. The effect of mutation carriage on the disease course was determined in the IgAN patient group. The frequency of MEFV mutations in IgAN or PGN was comparable to that found in ethnically adjusted general population (p = 0.1 and 0.5, respectively). Carriage of mutated MEFV was not associated with the course and severity of the disease or findings in kidney biopsy and urine analysis. In a population, mostly of Jewish extraction, MEFV mutations do not seem to predispose to the development of IgAN and other forms of PGN or affect the phenotype.