Please ensure Javascript is enabled for purposes of website accessibility
A Subset of Alzheimer's May Be Caused by Two Copies of a Single Gene: New Research
gvw_ap_news
By Associated Press
Published 3 weeks ago on
May 6, 2024

A long-feared gene appears to do more than raise people’s risk of Alzheimer’s: Inheriting two copies can cause the mind-robbing disease, according to research published in the journal Nature Medicine on Monday, May 6, 2024. (AP/David Duprey)

Share

Getting your Trinity Audio player ready...

WASHINGTON — For the first time, researchers have identified a genetic form of late-in-life Alzheimer’s disease — in people who inherit two copies of a worrisome gene.

Scientists have long known a gene called APOE4 is one of many things that can increase people’s risk for Alzheimer’s, including simply getting older. The vast majority of Alzheimer’s cases occur after age 65. But research published Monday suggests that for people who carry not one but two copies of the gene, it’s more than a risk factor, it’s an underlying cause of the mind-robbing disease.

The findings mark a distinction with “profound implications,” said Dr. Juan Fortea, who led the study the Sant Pau Research Institute in Barcelona, Spain.

Among them: Symptoms can begin seven to 10 years sooner than in other older adults who develop Alzheimer’s.

An estimated 15% of Alzheimer’s patients carry two copies of APOE4, meaning those cases “can be tracked back to a cause and the cause is in the genes,” Fortea said. Until now, genetic forms of Alzheimer’s were thought to be only types that strike at much younger ages and account for less than 1% of all cases.

Scientists say the research makes it critical to develop treatments that target the APOE4 gene. Some doctors won’t offer the only drug that has been shown to modestly slow the disease, Leqembi, to people with the gene pair because they’re especially prone to a dangerous side effect, said Dr. Reisa Sperling, a study coauthor at Harvard-affiliated Brigham and Women’s Hospital in Boston.

Sperling hunts ways to prevent or at least delay Alzheimer’s and “this data for me says wow, what an important group to be able to go after before they become symptomatic.”

But the news doesn’t mean people should race for a gene test. “It’s important not to scare everyone who has a family history” of Alzheimer’s because this gene duo isn’t behind most cases, she told The Associated Press.

How Do Genetics Affect Alzheimer’s?

More than 6 million Americans, and millions more worldwide, have Alzheimer’s. A handful of genes are known to cause rare “early-onset” forms, mutations passed through families that trigger symptoms unusually young, by age 50. Some cases also are linked to Down syndrome.

But Alzheimer’s most commonly strikes after 65, especially in the late 70s to 80s, and the APOE gene – which also affects how the body handles fats — was long known to play some role. There are three main varieties. Most people carry the APOE3 variant that appears to neither increase nor decrease Alzheimer’s risk. Some carry APOE2, which provides some protection against Alzheimer’s.

APOE4 has long been labeled the biggest genetic risk factor for late-in-life Alzheimer’s, with two copies risker than one. About 2% of the global population is estimated to have inherited a copy from each parent.

Research Points to a Cause for a Subset of Alzheimer’s

To better understand the gene’s role, Fortea’s team used data from 3,297 brains donated for research and from over 10,000 people in U.S. and European Alzheimer’s studies. They examined symptoms and early hallmarks of Alzheimer’s such as sticky amyloid in the brain.

People with two APOE4 copies were accumulating more amyloid at age 55 than those with just one copy or the “neutral” APOE3 gene variety, they reported in the journal Nature Medicine. By age 65, brain scans showed significant plaque buildup in nearly three-quarters of those double carriers – who also were more likely to have initial Alzheimer’s symptoms around that age rather than in the 70s or 80s.

Fortea said the disease’s underlying biology was remarkably similar to young inherited types.

It appears more like “a familial form of Alzheimer’s,” said Dr. Eliezer Masliah of the National Institute on Aging. “It is not just a risk factor.”

Importantly, not everyone with two APOE4 genes develops Alzheimer’s symptoms and researchers need to learn why, Sperling cautioned.

“It’s not quite destiny,” she said.

How the New Findings May Affect Alzheimer’s Research and Treatment

The drug Leqembi works by clearing away some sticky amyloid but Sperling said it’s not clear if carriers of two APOE4 genes benefit because they have such a high risk of a side effect from the drug – dangerous brain swelling and bleeding. One research question is whether they’d do better starting such drugs sooner than other people.

Masliah said other research aims to develop gene therapy or drugs to specifically target APOE4. He said it’s also crucial to understand APOE4’s effects in diverse populations since it’s been studied mostly in white people of European ancestry.

As for gene tests, for now they’re typically used only to evaluate if someone’s a candidate for Leqembi or for people enrolling in Alzheimer’s research – especially studies of possible ways to prevent the disease. Sperling said the people most likely to carry two APOE4 genes had parents who both got Alzheimer’s relatively early, in their 60s rather than 80s.

RELATED TOPICS:

DON'T MISS

Former Fresno Farm Water Manager Pleads Guilty to Federal Water Theft Conspiracy

DON'T MISS

Local Dealership Family Buys Fresno Infiniti. Where Is It Going?

DON'T MISS

California Bill Would End ‘Gender Police’ Reports From Public Schools to Parents

DON'T MISS

Councilmembers Want Answers on Lawsuit. We Have Them.

DON'T MISS

Fresno Toddler Receives Support With a Donated Mobility Ramp

DON'T MISS

Fresno Catholic Diocese Will File Bankruptcy Because of Sexual Abuse Claims: Bishop Brennan

DON'T MISS

Storm Damage Forces Removal of US-Built Gaza Pier for Repairs

DON'T MISS

Lexi Thompson, a 15-Time Winner on the LPGA Tour, Is Retiring From Full-Time Golf at 29

DON'T MISS

Trump Prosecutor Emphasizes ‘Cover-Up’ in Closing Arguments; Defense Targets Key Witness

DON'T MISS

Clovis Detectives Quickly Arrest Suspects in Construction Equipment Theft at Church

UP NEXT

Local Dealership Family Buys Fresno Infiniti. Where Is It Going?

UP NEXT

Councilmembers Want Answers on Lawsuit. We Have Them.

UP NEXT

Fresno Toddler Receives Support With a Donated Mobility Ramp

UP NEXT

Fresno Catholic Diocese Will File Bankruptcy Because of Sexual Abuse Claims: Bishop Brennan

UP NEXT

Storm Damage Forces Removal of US-Built Gaza Pier for Repairs

UP NEXT

Lexi Thompson, a 15-Time Winner on the LPGA Tour, Is Retiring From Full-Time Golf at 29

UP NEXT

Trump Prosecutor Emphasizes ‘Cover-Up’ in Closing Arguments; Defense Targets Key Witness

UP NEXT

Clovis Detectives Quickly Arrest Suspects in Construction Equipment Theft at Church

UP NEXT

Albert Ruddy, Oscar-Winning Producer of ‘the Godfather’ and ‘Million Dollar Baby,’ Dies at 94

UP NEXT

Who Bears Some Blame for High CA Gas Prices? Look in the Mirror

Councilmembers Want Answers on Lawsuit. We Have Them.

9 hours ago

Fresno Toddler Receives Support With a Donated Mobility Ramp

10 hours ago

Fresno Catholic Diocese Will File Bankruptcy Because of Sexual Abuse Claims: Bishop Brennan

11 hours ago

Storm Damage Forces Removal of US-Built Gaza Pier for Repairs

12 hours ago

Lexi Thompson, a 15-Time Winner on the LPGA Tour, Is Retiring From Full-Time Golf at 29

12 hours ago

Trump Prosecutor Emphasizes ‘Cover-Up’ in Closing Arguments; Defense Targets Key Witness

12 hours ago

Clovis Detectives Quickly Arrest Suspects in Construction Equipment Theft at Church

13 hours ago

Fresno ‘Flirts’ with Hot Weather. When Will Triple Digits Arrive?

13 hours ago

Albert Ruddy, Oscar-Winning Producer of ‘the Godfather’ and ‘Million Dollar Baby,’ Dies at 94

13 hours ago

Who Bears Some Blame for High CA Gas Prices? Look in the Mirror

13 hours ago

Former Fresno Farm Water Manager Pleads Guilty to Federal Water Theft Conspiracy

Dennis Falaschi — indicted two years ago in an alleged $25 million federal water theft — pleaded guilty to a single count of conspiring to s...

8 hours ago

8 hours ago

Former Fresno Farm Water Manager Pleads Guilty to Federal Water Theft Conspiracy

9 hours ago

Local Dealership Family Buys Fresno Infiniti. Where Is It Going?

9 hours ago

California Bill Would End ‘Gender Police’ Reports From Public Schools to Parents

9 hours ago

Councilmembers Want Answers on Lawsuit. We Have Them.

10 hours ago

Fresno Toddler Receives Support With a Donated Mobility Ramp

11 hours ago

Fresno Catholic Diocese Will File Bankruptcy Because of Sexual Abuse Claims: Bishop Brennan

12 hours ago

Storm Damage Forces Removal of US-Built Gaza Pier for Repairs

12 hours ago

Lexi Thompson, a 15-Time Winner on the LPGA Tour, Is Retiring From Full-Time Golf at 29

MENU

CONNECT WITH US

Search

Send this to a friend