AUG 25, 2019 3:03 PM PDT

APOE4 Carriers Have Memory Problems Before the Onset of Alzheimer's

WRITTEN BY: Carmen Leitch

Changes in the genes we carry can have a big impact on our risk of getting certain diseases. A variant of the apolipoprotein (APOE) gene is the most common genetic factor linked to Alzheimer’s disease development that we know of. There are three (or more) major classes of APOE gene variants, referred to as APOE2, APOE3, and APOE4. Now scientists have found that people who carry the APOE4 gene are not only at risk of developing Alzheimer’s disease. They may also experience problems with attention and memory, even when there are no obvious signs of illness. The findings have been outlined in Scientific Reports.

Image credit: Pixabay

In this study, 60 volunteers aged 40 to 61, who had different combinations of the APOE4 gene and normal hearing had to listen to 92 audio clips. One group of people carried APOE4 genes, another carried a combination of APOE4 and APOE3 genes, and the last group had APOE3 genes. They all fell in the normal range on their cognitive tests.

While listening to the audio clips, the participants noted whether the sound they heard was in their left, right, or in both ears. Incorrect assessments were replayed. Then they got a one hour break and repeated the listening, but also had to acknowledge another sound at the end of the clips, which they were told about. They pressed a button when they heard the new sound, and each clip was played twice - first without the new tone, then with.

All of the study participants could learn the new information and remember which ears heard the clip. But, the additional sound at the end was harder for the people with APOE4 to identify. The APOE4 carriers seemed to have a tougher time remembering information they’d just learned, and maybe greater difficulty accessing knowledge.

This work could lead to the development of new ways to detect individuals at risk.

"For some reason, people with the APOE4 gene were not able to take advantage of information they learned earlier, such as the expected location of the clip, to boost their performance," explained senior study author Dr. Claude Alain, a senior author on the paper and senior scientist at Baycrest Centre for Geriatric Care. "This study shows we have a test that is sensitive to capture problems or challenges faced by individuals with this gene, before their deficits are observed on a standard neuropsychological assessment."

"The research could lead to more sensitive methods of detecting Alzheimer's disease in its very earliest stages, the time at which treatments are most likely to be effective," said senior author Dr. Chris Butler, an associate professor in clinical neurosciences at the University of Oxford. "I was delighted to carry out this work with researchers from Baycrest."

Learn more about how the APOE4 plays a role in Alzheimer’s from the video above by Cell Press.

Sources: AAAS/Eurekalert! via Baycrest Centre for Geriatric Care, Scientific Reports

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
FEB 23, 2020
Genetics & Genomics
FEB 23, 2020
Revealing More About the Genetic Mechanisms Underlying Down Syndrome
Down syndrome impacts around 6,000 live births in the US every year. Around 95% of affected individuals have a type call ...
MAR 03, 2020
Cell & Molecular Biology
MAR 03, 2020
New CRISPR-HOT Technique Can Color Cells and Genes
Since the CRISPR/Cas9 editing tool was developed several years ago, many scientists have modified and improved it for di ...
MAR 04, 2020
Genetics & Genomics
MAR 04, 2020
DNA Fragments and Cartilage Recovered From 75-Million-Year-Old Dinosaur Bones
An international team of researchers has analyzed cartilage from a baby duckbilled dinosaur, and they have identified bi ...
MAR 23, 2020
Genetics & Genomics
MAR 23, 2020
Diagnosing Cancer by Looking for Microbial DNA in the Blood
Liquid biopsies aim to diagnose a disease with only a bit of biological fluid, usually blood.
MAR 30, 2020
Microbiology
MAR 30, 2020
The Microbial Communities That Form on the Tongue
Scientists used a fluorescent imaging tool to analyze how bacteria grow on the human tongue.
APR 19, 2020
Genetics & Genomics
APR 19, 2020
Two New Viruses IDed in Brazilian Patient Samples
After an assessment of blood samples collected in Brazil between 2013 and 2016, scientists have found two new species of ...
Loading Comments...