Abstract

INTRODUCTION

The Familial Mediterranean Fever (FMF) gene has been cloned to chromosome 16p and more than 50 different mutations have been identified. Ethnicity and environmental factors can change the phenotypic effects of mutations. We aimed to evaluate genotype-phenotype correlation in our patients.

METHODS

Eighty one children with FMF diagnosis based on Tel Hashomer criteria were enrolled in the study. Clinical and genetic features of the patients were retrospectively analyzed.

The relationship between mutations and phenotypic features along with severity of the disease were evaluated. Disease severity was assessed by using the modified scoring system of Pras.

RESULTS

The mean (±SD) age at onset of the diagnosis was 9.2±3.4 years. The most frequent symptoms of the patients were abdominal pain (98.8%) and arthralgia (80.2%). The disease severity level was mild in 32.1%, intermediate in 63%, and severe in 4.9% of the cases. Seven different MEFV gene mutations were found in 56 patients and 88 alleles; M694V was the most frequent mutation (30.2%). In the patients with M694V homozygous mutation, significantly higher frequency of arthritis was observed (p=0.04).

Although there was no statistically significant difference among different mutation groups, FMF severity score and the rate of amyloidosis were found higher in the patients with M694V/M694V genotype.

DISCUSSION AND CONCLUSION

Detection of MEFV mutation has been used to support the diagnosis of FMF. The clinician has to decide the treatment and follow-up procedure according to the clinical features and mutations. It should be kept in mind that amyloidosis is seen more frequently in the patients with M694V genotype.