Featured Research

from universities, journals, and other organizations

Variation In 3 Genes Influences Risk Of Age-related Macular Degeneration

Date:
September 7, 2006
Source:
Harvard Medical School
Summary:
Researchers in Boston have discovered a new common, noncoding variant in the Complement Factor H (CFH) gene that is associated with age-related macular degeneration (AMD), the leading cause of irreversible visual impairment and blindness among persons aged 60 and older. Their analyses, for the first time, combine this new variant with all previously reported variants to estimate individual risk of advanced AMD.

Researchers in Boston have discovered a new common, noncoding variant in the Complement Factor H (CFH) gene that is associated with age-related macular degeneration (AMD), the leading cause of irreversible visual impairment and blindness among persons aged 60 and older.

Their analyses, for the first time, combine this new variant with all previously reported variants to estimate individual risk of advanced AMD. They observed additive accumulation of risk from alleles at these three genes, including CFH on chromosome 1, complement factor B (BF) and complement component 2 (C2) genes on chromosome 6, and the LOC gene on chromosome 10. They estimate that genotypes related to five variants in these three genes explain about half the sibling risk of AMD in the study population. Results are published online in Nature Genetics.

The principal investigator, Johanna M. Seddon, M.D., Director of the Epidemiology Unit and Macular Degeneration specialist at the Massachusetts Eye and Ear Infirmary, and Associate Professor at Harvard Medical School, collaborated with co-authors from the Center for Human Genetic Research at Massachusetts General Hospital and the Program in Medical and Population Genetics, Broad Institute of Harvard and Massachusetts Institute of Technology. They studied 2,172 unrelated European-descended individuals 60 years of age or older, who were diagnosed on the basis of ocular examination and ocular photography (1,238 affected individuals and 934 controls). Affected individuals were defined as those having advanced AMD related to visual loss with either geographic atrophy (dry) or neovascular (wet) disease. Controls were individuals without AMD. The mean age was 74 for controls (54% female) and 78 years for affected individuals (55% female). Both Illumina and Sequenom methods were used to genotype about 1540 single nucleotide polymorphisms (snp's).

AMD is a "common disease" meaning that it is complex, i.e., many genes and environmental factors contribute to the disease, similar to heart disease, schizophrenia and diabetes. The combinations of variation within a given gene and between genes, along with environmental factors, confers one's lifetime risk of a disease like AMD. Variations in the BF/C2 gene are protective for AMD, whereas the more common variations in the other two genes, CFH and LOC, increase risk of AMD. The authors provide new calculations that one's lifetime risk of AMD ranges from less than 1% to more than 50%, depending on the variations one has in these three genes. The research team also showed that the three genes do not interact, but confer risk independently.

AMD is the leading cause of irreversible visual impairment and blindness among persons aged 60 and older. With the elderly population steadily growing, the burden related to this loss of visual function will increase. Limited treatment options exist and prevention remains the best approach for addressing this public health concern.

"The overall implication of this study is that depending on your genotype related to these five variants in three genes, and most likely more to be discovered, preventive and therapeutic drug targets may be better designed and tailored to an individual's need, ie., personalized medicine," said Dr. Seddon.

This study evaluated a large number of samples from individuals with advanced AMD, including both geographic atrophy or "dry" AMD, and neovascular disease or "wet" AMD, which cause visual loss. It is noteworthy that no differences were found between these subtypes of advanced AMD with respect to the variations found in the genes.

Dr. Seddon and her colleagues previously reported that the heritability of AMD is high (46% to 71%) in a large US cohort of elderly twins (Arch Ophthalmol 2005), and that another common CFH variant as well as smoking and higher body mass index are independently related to advanced AMD (Human Heredity 2006). A decade ago they reported the increased risk of AMD attributable to cigarette smoking (JAMA 1996). They also found that high body mass index is a risk factor for progression of the disease. (Arch Ophthalmol 2003).

Co-authors include the lead author Julian Maller from the Center for Human Genetic Research (CHGR), MGH, Sarah George from the Epidemiology Unit, MEEI, and Shaun Purcell, David Altshuler, and Mark Daly from CHGR, MGH and the Broad Institute. This most recent research was funded by grants from the National Institutes of Health, the Foundation Fighting Blindness Inc., the Massachusetts Lions Eye Research Fund, the Epidemiology Unit AMD Genetics Research Fund, and the Broad Institute Center for Genotyping and Analysis, supported by a grant form the National Center for Research Resources.


Story Source:

The above story is based on materials provided by Harvard Medical School. Note: Materials may be edited for content and length.


Cite This Page:

Harvard Medical School. "Variation In 3 Genes Influences Risk Of Age-related Macular Degeneration." ScienceDaily. ScienceDaily, 7 September 2006. <www.sciencedaily.com/releases/2006/08/060830075539.htm>.
Harvard Medical School. (2006, September 7). Variation In 3 Genes Influences Risk Of Age-related Macular Degeneration. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2006/08/060830075539.htm
Harvard Medical School. "Variation In 3 Genes Influences Risk Of Age-related Macular Degeneration." ScienceDaily. www.sciencedaily.com/releases/2006/08/060830075539.htm (accessed October 21, 2014).

Share This



More Health & Medicine News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

CDC Revamps Ebola Guidelines After Criticism

CDC Revamps Ebola Guidelines After Criticism

Newsy (Oct. 21, 2014) The Centers for Disease Control and Prevention have issued new protocols for healthcare workers interacting with Ebola patients. Video provided by Newsy
Powered by NewsLook.com
First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

Newsy (Oct. 21, 2014) A medical team has for the first time given a man the ability to walk again after transplanting cells from his brain onto his severed spinal cord. Video provided by Newsy
Powered by NewsLook.com
CDC Issues New Ebola Guidelines for Health Workers

CDC Issues New Ebola Guidelines for Health Workers

Reuters - US Online Video (Oct. 21, 2014) The U.S. Centers for Disease Control and Prevention has set up new guidelines for health workers taking care of patients infected with Ebola. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
'Cadaver Dog' Sniffs out Human Remains

'Cadaver Dog' Sniffs out Human Remains

AP (Oct. 21, 2014) Where's a body buried? Buster's nose can often tell you. He's a cadaver dog, specially trained to find human remains and increasingly being used by law enforcement and accepted in courts. These dogs are helping solve even decades-old mysteries. (Oct. 21) 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:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

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