Preliminary Evaluation for the Development of a Scoring System to Predict Homozygous M694V Genotype in Familial Mediterranean Fever Patients: A Single-Center Study.

OBJECTIVE

The aim of this study was to identify key parameters of a scoring system to be developed to predict the homozygous M694V genotype in patients clinically diagnosed with familial Mediterranean fever.

METHODS

This study was a cross-sectional analysis of 472 pediatric familial Mediterranean fever patients with a homozygous genotype on exon 10, followed at our tertiary pediatric rheumatology clinic between June 2016 and June 2023. The patients were categorized into 2 groups based on their genotypes: group 1 comprised 402 patients (85.2%) with the homozygous M694V genotype, whereas group 2 consisted of 70 patients (14.8%) with other homozygous genotypes. Demographic information, clinical manifestations, MEFV (Mediterranean fever) gene variant analysis, and treatment responses were recorded from the patients' medical charts.

RESULTS

The odds ratios for age at disease onset, arthritis, and chest pain were 0.892 (95% confidence interval [CI]: 0.832-0.958, p = 0.002), 2.565 (95% CI: 1.109-5.934, p = 0.028), and 2.351 (95% CI: 1.123-4.922, p = 0.023), respectively. A total of 60.7% of patients in group 1 had arthralgia, and 25% had erysipelas-like erythema, with these percentages were higher in group 1 compared with group 2 (p = 0.002, p = 0.001, respectively). Protracted febrile myalgia syndrome was detected in 1.5% of patients, all of whom had homozygous M694V genotype. Colchicine resistance was detected in 13.3% of patients, and all had homozygous M694V genotype.

CONCLUSIONS

This preliminary evaluation identified key parameters for a scoring system designed to predict the homozygous M694V genotype. A multicenter national study will further refine these parameters and develop the scoring system, which will aid clinicians in disease prognosis and therapeutic decision-making.