Alzheimer’s risk climbs close to parent’s age of onset

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If you’re about to turn 60 and know your mother has had Alzheimer’s disease since 65, at what age will the disease strike you?

A new study in JAMA Neurology shows that the closer a person get to the age at which their parent exhibited the first signs of Alzheimer’s, the more likely they are to have amyloid plaques in the brain, the cause of the cognitive decline associated with the disease.

In this study involving a cohort of 101 individuals, researcher Sylvia Villeneuve, an assistant professor at McGill University and a core faculty member at The Neuro’s McConnell Brain Imaging Centre, shows that the difference between a person’s age and the age of their parent at the onset of the disease is a more important risk factor than their actual age.

“A 60-year-old whose mother developed Alzheimer’s at age 63 would be more likely to have amyloid plaques in their brain than a 70-year-old whose mother developed the disease at age 85,” explains Villeneuve, also of the Douglas Mental Health University Institute and CIUSSS de l’Ouest-de-l’Île-de-Montréal.

Her team of scientists also found that the genetic impact of Alzheimer’s disease is much greater than previously thought.

“Upon examining changes in the amyloid biomarker in the cerebrospinal fluid samples from our subjects, we noticed that this link between parental age and amyloid deposits is stronger in women than in men. The link is also stronger in carriers of the ApoE4 gene, the so-called ‘Alzheimer’s gene,'” says Villeneuve.

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The researcher and her team successfully duplicated their results in two independent groups, one consisting of 128 individuals from a Washington University in St. Louis cohort, the other consisting of 135 individuals from a University of Wisconsin-Madison cohort. They also reproduced their results using an imaging technique that shows amyloid plaques directly in the brains of living persons.

Their study is paving the way for the development of inexpensive methods for the early identification of people at risk for Alzheimer’s disease.

Grants from a Canadian research chair, the Canadian Institutes of Health Research, the Canadian Foundation for Innovation, the Canadian Brain Research Fund, the Alzheimer Society of Canada, and the Fonds de recherche du Québec — Santé supported the work.

Source: Bruno Geoffrey for CIUSSS de l’Ouest-de-l’Île-de-Montréal/McGill University