Genetic mutation introduced into human genome protects against Alzheimer’s disease, research says

Scientists from the Université Laval Faculty of Medicine and CHU de Québec–Université Laval Research Centre were successful in editing the genome of human cells cultured in vitro to introduce a mutation offering protection from Alzheimer’s disease. This discovery’s details were recently published in The CRISPR Journal.

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Some genetic mutations increase the risk of developing Alzheimer’s disease, but there is a mutation that reduces this risk. This is a rare mutation identified in 2012 in the Icelandic population. The mutation has no known disadvantage for those who carry it and reduces the risk of developing Alzheimer’s disease. Using an improved version of the CRISPR gene editing tool, we have been able to edit the genome of human cells to insert this mutation.”

Jacques-P. Tremblay, Study Lead Author and Professor, Université Laval

The brains of Alzheimer’s patients have amyloid plaques, which have a toxicity level that is believed to cause neuron death. When an enzyme called beta-secretase cleaves the amyloid precursor protein, the amyloid plaques are formed. “The Icelandic mutation makes it harder for this enzyme to cleave the amyloid precursor protein. As a result, the formation of amyloid plaques is reduced,” elaborates Professor Tremblay.

Theoretically, the progression of the disease could be prevented or slowed down by introducing the Icelandic mutation into the genome of individuals at risk of developing Alzheimer’s.

Unfortunately, we can’t go back and repair the damage that caused neurons to die,” says the researcher. “The treatment would therefore be particularly suitable for people from families affected by the hereditary form of the disease, which manifests itself in memory problems from the age of 35 to 40.”

Jacques-P. Tremblay, Study Lead Author and Professor, Université Laval

Professor Tremblay adds, “If successful, it could also potentially be used to treat people with the most common form of Alzheimer’s, which occurs after age 65, at the earliest signs of the disease.”

The challenge now is to find a way to edit the genome of millions of brain cells. We are looking at different possibilities, including the use of non-infectious viruses, to deliver the editing complex inside neurons. Now that the proof of concept has been established in human cells in vitro, we will test this approach in mice that express Alzheimer’s disease.”

Jacques-P. Tremblay, Study Lead Author and Professor, Université Laval

“If the findings are conclusive, we hope to be able to conduct a small-scale study in people with mutations that cause the onset of Alzheimer’s at age 35 to 40,” concluded Professor Tremblay.