Objective. The clinical profile in familial Mediterranean fever (FMF), including its major manifestation, amyloidosis, is influenced by MEFV allelic heterogeneity and other genetic and/or environmental factors. In this study, we analyzed the contribution of genotypes at the MEFV and SAA1 loci to disease severity and to the development of amyloidosis, and further defined the factors affecting the clinical profile of FMF.Methods. We investigated a sample of 277 FMF patients (154 men and 123 women), including 62 patients with nephropathic amyloidosis, in whom both FMF alleles had been identified. A detailed chart review, interview, and physical examination were undertaken to determine the patients' demographic characteristics, medical history, clinical manifestations, and treatment. The disease severity score was calculated from the Tel-Hashomer key. Genotypes at the SAA1 locus (isoforms ␣, ␤, and ␥) were determined in all patients. The SAA1 13C/T polymorphism of the SAA1 promotor was analyzed in a subset of cases.Results