Featuring the phenotype of the FMF prototype

Background

The presentation of FMF is extremely variable, ranging from a quiescent to severe disabling disease. The M694V mutation is one of approximately 300 published genetic variations of MEFV and is thought to be associated with a typical clinical picture of the disease, but studies featuring the phenotype of homozygous M694V phenotype are meager.

Objectives

To describe the clinical trait of M694V homozygous FMF as compared to the phenotype of FMF with mixed MEFV genotypes.

Patients and methods

Fifty seven FMF patients homozygous for the M694V genotype were compared to 56 patients carrying other mutations. A questionnaire, including items related to demographic and clinical features was completed for each patient based on interview, physical examination and file notes.

Results

Compared with the control group, more patients, homozygous for the M694 mutation, suffered from a severe disease (p=0.001), had higher frequency of attacks before and during colchicine treatment (p=0.0001 and 0.0007, respectively), had more related diseases (p=0.0373) and needed higher dose of colchicine to control their disease (p=0.0001). Most other features tested (Table 1) appeared to be more pronounced in M694V homozygous patients (either with or without statistical significance).

Conclusion

The phenotype of FMF, as manifested in M694V homozygous patients, is the gold standard, to which other FMF presentations should be compared.

Table 1