HFE and hemochromatosis: Hemochromatosis occurs in 0.003 – 0.005 of persons of northwestern European descent, and is typically associated with homozygosity for the C282Y mutation of the HFE gene (exon 2, nt 845 G→A), located ~4 Mb telomeric to the human leukocyte antigen (HLA) region on Ch6p [1,2].