P01-037 – Genetic analysis practice prior to FMF diagnosis

Results At colchicine prescription, genetic results were not available for 229/681 patients (34%). A typical phenotype was significantly more common in this subgroup than in patients with genetic testing at prescription (212/229, 92%, vs. 260/452, 58%, OR=9.2 95% CI 5.4-15.6, p=0.0001). Of note, despite the high frequency of typical phenotype in this group, the rate of 2 pathogenic variants of MEFV was higher (61.5% vs. 49.3%, p=0.002), the rate of genetic negative FMF was lower (7% vs. 17.4%, p<0.0001), and the rate of p.M694V homozygosity tended to be higher (31% % vs. 25, a trend) in those with gene analysis available at prescription. When focusing on typical presentation alone (n=472), the distinction between the groups increased, as in the subgroup with typical phenotype plus genetic analysis prior to prescription the rates of 2 pathogenic variants and homozygosity to M694V were higher than in typical phenotype without genetic testing (60.7% vs. 50%, p=0.02, and 37% vs. 27%, p= 0.037 respectively).