On the other hand, Ammouri et al. [6] described 14 patients who had a recurrent fever syndrome with high level of IgD without MVK mutations and proposed to use the term of mevalonate kinase deficiency (MKD) for patients who have a biochemical deficiency of mevalonate kinase and MVK mutations and the term HIDS for the group of patients who have a recurrent fever syndrome and an elevated IgD concentration. The gene discussed is MVK; the disease is mevalonic aciduria.