Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Gene variation associated with brain atrophy in mild cognitive impairment

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. (

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. (

Linda Brooks | EurekAlert!
Further information:

More articles from Health and Medicine:

nachricht Resolving the mystery of preeclampsia
21.10.2016 | Universitätsklinikum Magdeburg

nachricht New potential cancer treatment using microwaves to target deep tumors
12.10.2016 | University of Texas at Arlington

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: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>