For all these reasons, future research should be aimed at recruiting more subjects with fibromyalgia and analyzing the cumulative effect of the risk alleles for the selected variants, as well as using genetic and serum analysis tools to observe the enzymatic behavior according to the presence of associated alleles to DAO deficiency in the population with fibromyalgia. The gene discussed is DAO; the disease is hyperinsulinemic hypoglycemia, familial, 4.