MEFV mutation frequency and effect on disease severity in ankylosing spondylitis.

BACKGROUND/AIM To define the frequency of familial Mediterranean fever gene (MEFV) mutations in ankylosing spondylitis (AS) and describe different clinical aspects of MEFV mutation carrier and noncarrier AS patients. MATERIALS AND METHODS In 112 AS patients, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Bath Ankylosing Spondylitis Functional Index (BASFI) scores were calculated. The frequencies of 12 different MEFV mutations were studied by multiplex polymerase chain reaction/reverse hybridization method and were compared to those of previously studied healthy controls for 5 common MEFV mutations. RESULTS MEFV mutations were identified in 46 of 224 (20%) alleles and in 39 (35%) of AS patients. The distribution of mutations was: M694V, 30% (14); E148Q, 30% (14); P369S, 17% (8); V726A, 13% (6); A744S, 8% (4); and K695R, 2% (1). There were no significant differences between MEFV mutation carriers and noncarriers with respect to sex, age of symptom onset, disease duration, peripheral joint involvement, acute phase reactant levels, and BASDAI and BASFI scores (P > 0.05 all). MEFV mutation allelic frequency was not different between AS patients and healthy controls after adjusting for mutations studied (34/224 versus 22/200; P > 0.05). CONCLUSION Although we did not find significant clinical and laboratory differences between MEFV mutation carrier and noncarrier AS patients, further investigations are needed to define the impact of MEFV mutations on AS disease course.