アルツハイマー病リスク予測の革新
Welcome to SCIEN-SPOT, the podcast that puts a spotlight on the latest discoveries in science
and technology. I am REN from SCIEN-TALK. Today we are exploring some big news from
Japan that could change the way we approach Alzheimer's diseases.
Alzheimer's disease is a major issue in Japan's aging society, but a research theme from Keio
University and Eizai, a Japanese pharmaceutical company, has made a big breakthrough. They've
developed a new way to predict someone's risk of getting Alzheimer's disease just by looking
at their genes. And it's made specifically for the Japanese population. Why is this important?
Well, Japan has one of the oldest populations in the world. By 2025, over 10 million people in
Japan are expected to have either dementia or something called mild cognitive impairment,
which often comes before dementia. And the most common cause of dementia is Alzheimer's disease.
It happens when harmful proteins, like one called amyloid beta, build up in the brain.
This can damage the brain cells and cause problems with memory, thinking, and decision making.
There's a new drug called lecanevab that can slow down this damage, but it only works if you catch
the disease early. That's why knowing your risk before symptoms appears is so important.
And that's exactly what this new research aims to help with.
The research uses something called the polygenic risk score, or PRS for short. Think of it like
this. Our DNA has thousands of small differences, and many of them can slightly increase or decrease
our risk of getting certain diseases. PRS adds up the effects of all these tiny differences to give
you a number. This is a score that shows how likely you are to get a disease like Alzheimer's.
And it's like predicting your chances based on your genetic blueprint.
You may have heard of a gene called APOE. If you have a version called APOE4, your risk is higher.
If you have APOE2, your risk is lower. But PRS goes beyond that. It looks at many other genes too,
日本のアルツハイマー予測モデル
not just APOE. Until now, most of these PRS models were made using data from western countries,
but Japanese people have different genetic backgrounds, so those models didn't always
work well in Japan. The Keio and EZAI team used data from Japanese patients to build their PRS
model just for Japanese people. They looked at a large group of patients with Alzheimer's
and studied their DNA. Then, they focused on a special brain scan called an amyloid beta PET
scan. This scan shows whether amyloid beta has built up in the brain, something that often
happens before symptoms begin. By analyzing the DNA and the scan results, the researchers found a
way to predict with good accuracy whether a person is likely to have this harmful protein in their
brain. They tried different methods to calculate the PRS and found that including the APOE gene
made the prediction much better. The final model had a prediction score called AUC of 0.76,
which is considered very good, and they tested it on another set of Japanese data
and got similar results. That means it really works.
日本向けのアルツハイマーリスクモデル
So this is the first time we've had a genetic risk model that works well for Japanese people.
That's a big step forward. It means people could find out early if they're at higher risk and take
action like changing their lifestyle or getting medical advice sooner. But there's a catch.
Genes alone don't decide everything. Things like your diet, exercise, sleep,
and even how socially connected you are also matter. So a high genetic score doesn't mean
you will get Alzheimer's. It just means your risk is higher. That's why this is a tool,
not a final answer. To use this in hospitals or clinics, researchers need to test it on
more people and make sure it works for different groups.
Because this involves personal genetic data, we also need to think about privacy and ethics.
Still, this research is exciting, and it could help Japan and maybe the world
get better at preventing Alzheimer's before it starts. And that's something worth celebrating.
And yes, that's it. SciencePod is available every weekday morning in both Japanese and English.
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using the hashtag SciencePod. Thanks for listening and see you next time.
