MVK and mevalonic aciduria: Mevalonate kinase deficiency (MKD) is a rare autoinflammatory autosomal recessive periodic fever disorder.1,2 Hyperimmunoglobulinemia D and periodic fever syndrome (HIDS) and mevalonic aciduria (MA) are both part of the MKD spectrum.3,4 They result from mutations in the gene encoding mevalonate kinase (MK).