Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


New genetic discovery explains 74 percent cases of age-related macular degeneration


Significant advance for understanding leading cause of blindness in elderly

A new study, led by researchers at Columbia University Medical Center, pinpoints the role that two genes – Factor H and Factor B – play in the development of nearly three out of four cases of age-related macular degeneration (AMD), a devastating eye disease that affects more than 10 million people in the United States.

Findings indicate that 74 percent of AMD patients carry certain variants in one or both genes that significantly increase their risk of this disease.

Published in Nature Genetics, the research is a continuation of work published last year by the same team in the Proceedings of the National Academy of Sciences (PNAS, April 30, 2005 issue, see Columbia press release: Led by Rando Allikmets, Ph.D., the Acquavella Associate Professor in Ophthalmology, Pathology and Cell Biology at Columbia University Medical Center, the research team included collaborating groups headed respectively by Gregory Hageman, Ph.D., professor of ophthalmology and visual sciences at the University of Iowa Roy J. and Lucille A. Carver College of Medicine, and by Michael Dean, Ph.D., at the National Cancer Institute of the National Institutes of Health.

The PNAS study showed that several variants in the Factor H gene significantly increase the risk of developing AMD. Factor H encodes a protein that helps shut down an immune response against bacterial or viral infection, once the infection is eliminated. People with these inherited risk-increasing variations of Factor H are less able to control inflammation caused by infectious triggers, which may spark AMD later in life.

Though the effect of Factor H on AMD is large, variation in this gene alone does not fully explain who gets AMD and who doesn’t. As described in the PNAS paper, about one-third (29 percent) of people with a Factor H risk variant had not been diagnosed with AMD.

The investigators decided to look for additional culprits and focused on genes in the same immune response pathway that contains Factor H.

Their genetic analysis of 1,300 people quickly identified Factor B as the major modifier of the disease. The discovery makes good biological sense: while Factor H is an inhibitor of the immune response to infection, Factor B is an activator. Because of the complementary roles of the these two genes, a protective Factor B variation can protect against AMD, even if one carries a risk-increasing variant of Factor H, and vice versa.

As described in Nature Genetics, the two genes explained nearly three out of four AMD cases: 74 percent of the subjects with AMD had either the Factor H or Factor B risk variant (or both), but no protective variants of either gene.

"I am not aware of any other complex disorder where nearly 75 percent of genetic causality has been identified," said Dr. Rando Allikmets, who is senior author of the paper.

"These findings are significant because they absolutely confirm the roles of these two genes and, consequently, the central role of a specific immune response pathway, in the development of AMD. We confirmed this association not just statistically and genetically but, most importantly, pinpointed the biological origin of the disease," added Dr. Allikmets. "In just a few short years, we’ve gone from knowing very little about what causes AMD to knowing quite a lot. We now have clear targets for early therapeutic intervention."

Though the new paper explains much of the genetic risk, the specific triggers that set off the immune response and subsequent inflammation are still unknown. Researchers at Columbia University Medical Center and the University of Iowa are now searching for specific viral and bacterial culprits.

"It is my sincere pleasure to work with this talented team and to be involved in these important studies that identify the genetic basis for the role of the complement system – a pathway that my colleagues and I identified a number of years ago – in this truly devastating disease," said Dr. Hageman.

More than 50 million people worldwide are estimated to have irreversible blindness as a result of macular degeneration, making it the most common cause of blindness for those over 60. It’s estimated that 30 percent of the population will have some form of AMD by the time they reach the age of seventy-five. The disease is marked by a progressive loss of central vision due to degeneration of the macula--a region of the retina and the area responsible for fine, central vision.

Elizabeth Streich | EurekAlert!
Further information:

More articles from Studies and Analyses:

nachricht Diagnoses: When Are Several Opinions Better Than One?
19.07.2016 | Max-Planck-Institut für Bildungsforschung

nachricht High in calories and low in nutrients when adolescents share pictures of food online
07.04.2016 | University of Gothenburg

All articles from Studies and Analyses >>>

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

New method increases energy density in lithium batteries

24.10.2016 | Power and Electrical Engineering

International team discovers novel Alzheimer's disease risk gene among Icelanders

24.10.2016 | Life Sciences

New bacteria groups, and stunning diversity, discovered underground

24.10.2016 | Life Sciences

More VideoLinks >>>