MEFV and familial Mediterranean fever: The development of genetic testing of the MEFV gene in the clinical setting with the increment in diagnosed patients of FMF has reached the consensus that approximately 30% of the diagnosed FMF cases clinically carry only one demonstrable mutation despite the extensive search for a second disease-causing variant [2] which indicates that a single pathogenic MEFV mutation, with other genetic or environmental factors, might be sufficient to induce the activation of the pyrin inflammasome.