Genetic and clinical features of familial Mediterranean fever in a cohort of patients with kidney failure.

Background: Familial Mediterranean fever (FMF) often manifests as recurrent inflammatory episodes, potentially leading to secondary amyloidosis. Many studies have assessed the clinical correlation between FMF and Mediterranean fever (MEFV) gene variants (FMF type I). However, few studies have focused on patients who remain relatively asymptomatic and present with renal amyloidosis (FMF type II). We hypothesize that patients with kidney failure carry higher rates of FMF variants. Therefore, our study aimed to assess the rates and types of FMF gene variants in a cohort of patients with kidney failure compared to healthy controls of the same area.

Methods: This is a cross-sectional study involving a hemodialysis cohort compared to healthy controls. The controls were healthy university students recruited from the Hashemite University campus. Both groups underwent genetic screening for FMF using polymerase chain reaction and reverse hybridization. Patients with positive genetic screening were offered a colonoscopy with rectal biopsies, which were assessed for the deposition of amyloid proteins.

Results: Genetic analysis of the cohort of patients with kidney failure revealed remarkable differences in allele frequency rates across different genotypes. The positivity rate in the hemodialysis cohort reached 16.0%, compared to 12.9% in the healthy controls (p = 0.342, X² = 0.902). Among the different genotypes, V726A and M694V were significantly different between the two groups, with p-values of 0.009 and 0.035, respectively.

Conclusion: In our population, patients with kidney failure carried a higher allele frequency of some FMF variants than healthy controls. The M694V and V726A mutations were associated with kidney failure.