Objectives: Familial Mediterranean fever (FMF) is an autosomal recessive disease, characterised by recurrent, self limited attacks of fever with serositis. The aim of our study was to describe the demographic, clinical and genetic features of FMF patients who had early disease onset and to compare them with late onset patients. Our second aim was to investigate the factors associated with delay in diagnosis.
Methods: The study group consisted of recently diagnosed FMF patients who came to routine follow-up visits between January and July 2009. Patients were divided into two groups according to age of disease onset (Group I: ≤ 3 years of age; Group II: >3 years of age). In the second part, patients were analysed according to the duration of delay in diagnosis.
Results: There were 83 patients in group I and 73 patients in Group II. Median delay in diagnosis was 4 years in Group I and 2 years in Group II (p<0.001). The presence of M694V mutation was more frequent in Group I (81%) as compared to Group II (65%), (p=0.034). Mean attack Hb was lower (p<0.01) and mean attack leukocyte count was higher (p=0.017) in Group I. Final colchicine dosages were higher in Group I as compared to Group II. There was a statistically significant negative correlation between the age at disease onset and period of delay in diagnosis (p<0.001).
Conclusions: This study suggests that FMF patients with early disease onset have more severe disease. Moreover, the smaller the age of disease onset, the more likely their diagnoses are delayed.