ADK deficiency was described in 2011 (Bjursell et al 2011) and to date, 20 patients have been published in the literature (Bjursell et al 2011; Staufner et al 2016a; Labrune et al 1990—initial diagnosis was suspected to be SAHH deficiency and the correct diagnosis has been established recently). The gene discussed is ADK; the disease is hyperinsulinemic hypoglycemia, familial, 4.