Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Gene variation associated with brain atrophy in mild cognitive impairment

14.01.2014
The presence of a gene variant in people with mild cognitive impairment (MCI) is associated with accelerated rates of brain atrophy, according to a new study published online in the journal Radiology.

The study focused on the gene apolipoprotein E (APOE), the most important genetic factor known in non-familial Alzheimer's disease (AD). APOE has different alleles, or gene variations, said the study's senior author, Jeffrey R. Petrella, M.D., associate professor of radiology at Duke University School of Medicine in Durham, N.C.


Medial, inferior, superior, and lateral images of a three-dimensional FreeSurfer reference brain model show regions of accelerated atrophy in the presence of APOE epsilon 4 in subjects with MCI. Effect size of the APOE epsilon 4 acceleration of cortical atrophy is depicted by color: Blue signifies a magnitude of Cohen d value of less than 0.25; yellow, 0.25𔂾.35; and red, more than 0.35. Gray areas were not examined.

Credit: Radiological Society of North America

"We all carry two APOE alleles, and most people have at least one copy of the APOE epsilon 3 (ɛ3) variant, which is considered neutral with respect to Alzheimer's risk," Dr. Petrella said.

The less common epsilon 4 (ɛ4) allele, in contrast, is associated with a higher risk for development of AD, earlier age of onset, and faster progression in those affected, as compared with the other APOE alleles.

Dr. Petrella and colleagues recently analyzed data from the Alzheimer's Disease Neuroimaging Initiative (ADNI) involving 237 patients, mean age 79.9, with MCI, a slight but noticeable decline in cognitive ability that is tied to a higher risk of AD. The researchers used MRI to measure brain atrophy rates in these patients over a 12- to 48-month period.

The ɛ4 carriers in the study group exhibited markedly greater atrophy rates than ɛ3 carriers in 13 of 15 brain regions hypothesized to be key components of the cognitive networks disrupted in AD.

"The results showed atrophy in brain regions we know are affected by AD, in a population of patients who do not have AD, but are at risk for it," Dr. Petrella said. "This suggests the possibility of a genotype-specific network of related brain regions that undergo faster atrophy in MCI and potentially underlies the observed cognitive decline."

The researchers did not explore why APOE ɛ4 might accelerate atrophy, but the affect is likely due to a combination of factors, noted Dr. Petrella.

"The protein has a broad role in the transport and normal metabolism of lipids and a protective function on behalf of brain cells, including its role in the breakdown of beta-amyloid, one of the proteins implicated in the pathophysiology of AD," he said.

With MRI playing an increasingly prominent role in MCI research, Dr. Petrella predicted that increased knowledge about the effects of APOE will improve the design and execution of future clinical trials. For instance, researchers could enrich their samples with å4 patients in MCI prevention trials to better determine potential treatment effects on brain regions vulnerable to degeneration.

The advances in knowledge will also help expand the role of MRI measures in clinical trials investigating novel drugs with potentially disease-modifying capabilities.

"Current FDA-approved drugs treat symptoms, but don't modify the underlying cause of the disease," Dr. Petrella said. "We want to make continued inroads toward the goal of developing and testing drugs that modify the disease process itself."

"Mapping the Effect of the Apolipoprotein E Genotype on 4-Year Atrophy Rates in an Alzheimer's Disease-related Brain Network." Collaborating with Dr. Petrella were Christopher A. Hostage, M.D., Kingshuk Roy Choudhury, Ph.D., and P. Murali Doraiswamy, M.B.B.S., FRCP. For the Alzheimer's Disease Neuroimaging Initiative.

Radiology is edited by Herbert Y. Kressel, M.D., Harvard Medical School, Boston, Mass., and owned and published by the Radiological Society of North America, Inc. (http://radiology.rsna.org/)

RSNA is an association of more than 53,000 radiologists, radiation oncologists, medical physicists and related scientists promoting excellence in patient care and health care delivery through education, research and technologic innovation. The Society is based in Oak Brook, Ill. (RSNA.org)

Linda Brooks | EurekAlert!
Further information:
http://RadiologyInfo.org
http://radiology.rsna.org

More articles from Health and Medicine:

nachricht For drivers with telescopic lenses, driving experience and training affect road test results
30.03.2015 | Wolters Kluwer Health

nachricht Precocious GEM: Shape-shifting sensor can report conditions from deep in the body
30.03.2015 | National Institute of Standards and Technology (NIST)

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Experiment Provides the Best Look Yet at 'Warm Dense Matter' at Cores of Giant Planets

In an experiment at the Department of Energy's SLAC National Accelerator Laboratory, scientists precisely measured the temperature and structure of aluminum as...

Im Focus: Energy-autonomous and wireless monitoring protects marine gearboxes

The IPH presents a solution at HANNOVER MESSE 2015 to make ship traffic more reliable while decreasing the maintenance costs at the same time. In cooperation with project partners, the research institute from Hannover, Germany, has developed a sensor system which continuously monitors the condition of the marine gearbox, thus preventing breakdowns. Special feature: the monitoring system works wirelessly and energy-autonomously. The required electrical power is generated where it is needed – directly at the sensor.

As well as cars need to be certified regularly (in Germany by the TÜV – Technical Inspection Association), ships need to be inspected – if the powertrain stops...

Im Focus: 3-D satellite, GPS earthquake maps isolate impacts in real time

Method produced by UI researcher could improve reaction time to deadly, expensive quakes

When an earthquake hits, the faster first responders can get to an impacted area, the more likely infrastructure--and lives--can be saved.

Im Focus: Atlantic Ocean overturning found to slow down already today

The Atlantic overturning is one of Earth’s most important heat transport systems, pumping warm water northwards and cold water southwards. Also known as the Gulf Stream system, it is responsible for the mild climate in northwestern Europe. 

Scientists now found evidence for a slowdown of the overturning – multiple lines of observation suggest that in recent decades, the current system has been...

Im Focus: Robot inspects concrete garage floors and bridge roadways for damage

Because they are regularly subjected to heavy vehicle traffic, emissions, moisture and salt, above- and underground parking garages, as well as bridges, frequently experience large areas of corrosion. Most inspection systems to date have only been capable of inspecting smaller surface areas.

From April 13 to April 17 at the Hannover Messe (hall 2, exhibit booth C16), engineers from the Fraunhofer Institute for Nondestructive Testing IZFP will be...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

World Conference On Regenerative Medicine 2015: Registration And Abstract Submission Now Open

25.03.2015 | Event News

University presidents from all over the world meet in Hamburg

19.03.2015 | Event News

10. CeBiTec Symposium zum Big Data-Problem

17.03.2015 | Event News

 
Latest News

NASA's Hubble and Chandra Discover Dark Matter Is Not as Sticky as Once Thought

31.03.2015 | Physics and Astronomy

UAB Rolls Out New Technology to Help Users Combat Mobile Malware Attacks

31.03.2015 | Information Technology

The Dawn of DUNE

31.03.2015 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>