Featured Research

from universities, journals, and other organizations

Gene variation associated with brain atrophy in mild cognitive impairment

Date:
January 14, 2014
Source:
Radiological Society of North America
Summary:
The presence of a gene variant in people with mild cognitive impairment is associated with accelerated rates of brain atrophy, according to a new study.

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, 0.25 .35; and red, more than 0.35. Gray areas were not examined.
Credit: Radiological Society of North America

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.

"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 ε4 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."


Story Source:

The above story is based on materials provided by Radiological Society of North America. Note: Materials may be edited for content and length.


Journal Reference:

  1. Jeffrey R. Petrella, M.D. et al. Mapping the Effect of the Apolipoprotein E Genotype on 4-Year Atrophy Rates in an Alzheimer's Disease-related Brain Network. Radiology, January 2014

Cite This Page:

Radiological Society of North America. "Gene variation associated with brain atrophy in mild cognitive impairment." ScienceDaily. ScienceDaily, 14 January 2014. <www.sciencedaily.com/releases/2014/01/140114091943.htm>.
Radiological Society of North America. (2014, January 14). Gene variation associated with brain atrophy in mild cognitive impairment. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2014/01/140114091943.htm
Radiological Society of North America. "Gene variation associated with brain atrophy in mild cognitive impairment." ScienceDaily. www.sciencedaily.com/releases/2014/01/140114091943.htm (accessed July 23, 2014).

Share This




More Health & Medicine News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Idaho Boy Helps Brother With Disabilities Complete Triathlon

Idaho Boy Helps Brother With Disabilities Complete Triathlon

Newsy (July 23, 2014) An 8-year-old boy helped his younger brother, who has a rare genetic condition that's confined him to a wheelchair, finish a triathlon. Video provided by Newsy
Powered by NewsLook.com
Stone Fruit Listeria Scare Causes Sweeping Recall

Stone Fruit Listeria Scare Causes Sweeping Recall

Newsy (July 22, 2014) The Wawona Packing Company has issued a voluntary recall on the stone fruit it distributes due to a possible Listeria outbreak. Video provided by Newsy
Powered by NewsLook.com
Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Newsy (July 22, 2014) The 83 new genetic markers could open dozens of new avenues for schizophrenia treatment research. Video provided by Newsy
Powered by NewsLook.com
CDC Head Concerned About a Post-Antibiotic Era

CDC Head Concerned About a Post-Antibiotic Era

AP (July 22, 2014) Sounding alarms about the growing threat of antibiotic resistance, CDC Director Tom Frieden warned Tuesday if the global community does not confront the problem soon, the world will be living in a devastating post-antibiotic era. (July 22) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins