I Carry the R202Q Variant Only, Can I Have the Classical Clinical Features of Familial Mediterranean Fever?

Abstract

Objective: Familial Mediterranean fever (FMF) is a hereditary autoinflammatory disease characterized by self-limited fever and polyserositis. The disease is associated with mutations in the Mediterranean fever (MEFV) gene, of which more than 700 variants have been reported. This study aimed to evaluate the clinical features of children with FMF carrying the R202Q variant by comparing them with other common MEFV variants. Methods: This retrospective study included 318 patients who were previously diagnosed with FMF according to the Tel Hashomer criteria. Demographic and clinical data of patients with either heterozygous or homozygous FMF for R202Q variants (group 1) and patients with homozygous or compound heterozygous variants (M694V, M694I, M680I, V726A, E148Q etc.) (group 2) were compared Results: The R202Q group had a lower frequency of family history of FMF, recurrent fever, abdominal pain, chest pain, erysipelas-like erythema, and growth retardation (p=0.007, p=0.01, p=0.002, p=0.007, p=0.002 and p=0.05 respectively), and higher incidences of arthralgia, myalgia, oral ulcer, and headache (p=0.01, p=≤0.001, p=0.003, p=0.01 respectively). Group 2 had a higher rate of moderate projected retained ability score (PRAS) < scores, whereas group 1 had milder PRAS scores (p=≤0.001). The mean serum amyloid A value of the R202Q group was lower than that of group 2 (p=0.03). Conclusion: Although prospective studies on larger populations are needed to investigate the relationship between the clinical reflection of FMF and the R202Q variant, we suggest that R202Q alterations may be symptomatic in some patients.

Keywords

• fmf
• r202q
• variant
• heterozygous
• homozygous