Mevalonate Kinase Deficiency (MKD), a rare autoinflammatory disease (OMIM no. 251170), is caused by mutations in the second enzyme of the mevalonate pathway (mevalonate kinase (MK)) resulting in reduced enzymatic activity and in the consequent shortage of downstream compounds [1]. This evidence concerns the gene MVK and hyperinsulinemic hypoglycemia, familial, 4.