A rare mutation discovered linked to early-onset Alzheimer disease (AD) points to a new pathogenic mechanism for the disease and suggests a new target for treating the disease, according to research reported in the September issue of Nature Neuroscience.
Scientists previously identified mutations in the amyloid precursor protein (APP) gene linked to early-onset disease, mutations that result in increased production of amyloid β-protein (Aβ), a component of the amyloid plaques in the brains of people with AD. However, in the new work, researchers from the Karolinska Institute, in Huddinge, Sweden, and collaborators discovered a mutation in members of an AD-prone family from northern Sweden that results in low levels of Aβ but allows the formation of higher levels of protofibrils, small protein complexes that are an intermediate step in the formation of amyloid plaques. This discovery "may reflect an alternative pathogenic mechanism for AD involving rapid Aβ protofibril formation," the researchers noted.
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