In 1996, diagnostic criteria for hemochromatosis changed after the discovery that ~90% of non-Hispanic white adults with hemochromatosis are homozygous for the HFE (homeostatic iron regulator; chromosome 6p22.2) p.C282Y allele (exon 4, c.845G>A; rs1800562) [2,3] and that HFE p.C282Y homozygosity occurs in 0.3–0.6% of non-Hispanic whites [3]. The gene discussed is HFE; the disease is hemochromatosis type 1.