Study uncovers novel mechanism in rare mutation associated with Alzheimer's A novel mechanism has been identified that might explain why a rare mutation is associated with familial Alzheimer's disease in a new study by investigators at the University of Chicago. The paper, published on April 2 in the Journal of Experimental Medicine, characterizes a mutation located in a genetic region that was not previously thought be pathogenic, upending assumptions about what kinds of mutations can be associated with Alzheimer's Disease. Alzheimer's, a neurodegenerative disease that currently affects more than 6 million Americans, has been characterized by the accumulation of Aβ peptide into plaques in the spaces between neurons in the brain. These Aβ peptide are generated when a larger precursor protein, APP, is cleaved into smaller fragments as APP transits through different cellular compartments.