BMC Med Genet 2004, 5(4): http://www.biomedcentral.com/1471-2350/5/4
Medlej-Hashim,Myrna; Delague,Valerie; Chouery,Eliane; Salem,Nabiha; Rawashdeh,Mohammed; Lefranc,Gerard; Loiselet,Jacques; Megarbane,Andre
Background: Familial mediterranean fever (FMF) is a recessively inherited disease characterized
by recurrent crises of fever, abdominal, articular and/or thoracic pain. The most severe
complication is the development of renal amyloidosis. Over 35 mutations have been discovered so
far in the gene responsible for the disease, MEFV. This article aims at determining a correlation
between the MEFV genotype and the occurence of amyloidosis in FMF patients, in addition to the
study of the modifying effects of the SAA1 (type 1 serum amyloid A protein) and MICA (Major
Histocompatibility Complex (MHC) class-I-chain-related gene A) genes on this severe
complication.
Methods: Fourteen MEFV mutations were screened and the SAA1 and MICA polymorphisms tested
in 30 FMF patients with amyloidosis and 40 FMF patients without amyloidosis.
Results: The M694V and V726A allelic frequencies were, respectively, significantly higher and
lower in the group with amyloidosis, compared to the control FMF group. The beta and gamma
SAA1 alleles were more frequently encountered in the group without amyloidosis, whereas the
alpha allele was significantly more observed in FMF patients with amyloidosis (p < 0.025). All the
MICA alleles were encountered in both patients' groups, but none of them was significantly
associated with amyloidosis.
Conclusions: The results suggest a protective effect of the SAA1 beta and gamma alleles on the
development of amyloidosis and show the absence of a MICA modifying effect on amyloidosis
development. Testing these polymorphisms on a larger sample will lead to more definite
conclusions.