Alzheimer’s Gene Data

This week, the Alzheimer’s Association announced a plan to make gene sequencing data available to dementia researchers around the globe. Meanwhile, a new study shows that when people know their genetic risk of Alzheimer’s, many take positive steps to improve their mental and physical health.

The Alzheimer’s Association has teamed up with the Brin Wojcicki Foundation, established by Google co-founder Sergey Brin and Anne Wojcicki, a co-founder of personal genetics company 23andMe. The organizations have collected whole genome sequencing data from 800 Alzheimer’s patients and their families. Whole genome sequencing involves spelling out the more than three billion letters that make up a person’s DNA.

The data will be made available to scientists through the Global Alzheimer’s Association Interactive Network (GAAIN), and researchers hope the data will help them tease out risk factors for the nation’s sixth leading cause of death.

Dr. Robert C. Green of Brigham and Women’s Hospital and Harvard Medical School, who led the gene sequencing of patients in the Alzheimer’s Disease Neuroimaging Initiative (ADNI), told the Boston Business Journal that Alzheimer’s gene data has already been put to good use, with more breakthroughs on the way.

“With the addition of more than 800 whole genomes on ADNI subjects that can be linked to the current rich dataset, ADNI data will be even more useful to scientists who are seeking new approaches to the treatment and prevention of Alzheimer’s,” Green said. “ADNI is a leader in open data sharing, having provided clinical imaging and biomarker data to over 4,000 qualified scientists around the world, which has generated over 700 scientific manuscripts.”

Does Knowing Your Risk of Alzheimer's Make a Difference?

There’s a specific genetic risk marker for Alzheimer’s called APOe4. Patients who have two copies of this gene have the greatest risk of developing the disease.

As part of a study also led by Green of Brigham and Women's Hospital, 648 people were tested for APOe4 and learned their risk estimate, based on their genes, gender, ethnicity, and family history. Only four percent of participants had two copies of APOe4, while 34 percent had one copy of the gene and 62 percent did not carry the risk marker at all.

Perhaps surprisingly, though there is no cure for dementia, patients who knew they carried APOe4 were not measurably more depressed or anxious than non-carriers after a one-year follow-up. In fact, many turned over a new leaf.

"We saw that, following their genetic counseling session, people took positive steps to mitigate their Alzheimer's risk, such as following a healthy diet and exercising,” said lead study author Dr. Jason Karlawish, a professor of Medicine and Medical Ethics and Health Policy at the University of Pennsylvania’s Perelman School of Medicine, in a press release. “They might also be willing to join an Alzheimer's dementia prevention trial."

So should we all rush to our doctors for genetic testing? Karlawish says it’s a weighty decision, so before you ask your doctor, be sure to do your homework.

“If a healthy person wants to know their genetic risk of Alzheimer’s disease, I would recommend that they learn from the NIH, ADEAR, and Alzheimer’s Association websites about the risk factors for Alzheimer’s and the strengths and limitations of Alzheimer’s genetic testing,” Karlawish told Healthline. “After that education and reflection, if they want testing, they can consider commercial options.”

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