A hemochromatosis allele that protects against Alzheimer's disease injury: A role for H-ferritin.

Recent epidemiological evidence showed that mutations to the HFE-63 allele of this hemochromatosis-associated iron-assimilation protein improve chances of avoiding Alzheimer's disease (AD). This is unexpected since increased brain ferroptosis in gray-matter increases the risk for vascular dementia and AD. However, diffusion tensor imaging from a key Alzheimer's Disease Neuroimaging Initiative biomarker study showed that the hemochromatosis H63D allele protected white matter tracts and improved cognitive performance in individuals when APOE4 accelerates AD. H63D-carrying individuals exhibit elevated serum ferritin levels. We suggest coordinate increased levels of H-ferritin in iron-rich oligodendrocytes in H63D carriers generates sufficient neuroprotection to enhance myelin sheath integrity in white matter axons.