Familial Mediterranean fever (FMF) is an autosomal recessive disease characterised by recurrent attacks of fever and serositis. Amyloidosis is the most significant complication of FMF, leading to end stage renal disease (ESRD). Recently the gene (MEFV) causing this disease was cloned and more than 18 mutations have been identified. The hypothesis that the development of amyloidosis is associated with one of these mutations was tested.
23 patients with FMF and ESRD were analysed for their MEFV mutations and correlated with their corresponding rectal and renal biopsies. As case controls 23 patients with FMF free of renal disease, but with similar origin, sex, age, and age at onset of FMF, were chosen.
All the patients with ESRD induced by amyloidosis were homozygous for the M694V or M694I mutations. This finding was significantly different from that seen in the control group.
Amyloidosis is highly associated with the 694 substitution in the MEFV gene causing FMF. It seems that genetic predisposition plays a part in the development of this complication of FMF.