Navigation Links
Gene Linked With Aggressive 'Wet' Form Of AMD

Two recent articles in Science by researchers at Yale School of Medicine has reported about a gene variant that increases the risk of developing //the aggressive 'wet' form of age-related macular degeneration (AMD), the most common cause of blindness in people over age 50.

AMD causes light-sensitive cells in the retina to break down, resulting in progressive loss of central vision. Of the two forms of AMD, the 'dry' is more common than the 'wet' form. Wet macular degeneration can rapidly lead to blindness, while the dry AMD progresses more slowly.

Last year, Josephine Hoh, associate professor in the Departments of Epidemiology & Public Health and Ophthalmology at Yale and senior author on one of the two new studies, identified a gene for dry AMD and found that both wet and dry AMD are associated with a variant in the complement factor H (CFH) gene on chromosome 1.

Hoh now reports they have found a single nucleotide polymorphism (SNP)—a one-base change in the sequence—of the regulatory part of the HTRA1 gene on chromosome 10 that leads to greatly increased risk of developing the wet form of AMD.

According to Hoh, buildup of abnormal blood vessels in Caucasian patients is compounded by development of large waste deposits called drusen. Chinese patients, she said, develop little to no drusen and progress directly to wet AMD. This study demonstrates that these two major genes, CFH and HTRA1, in two different biological pathways, each affect the risk for a distinct component of the AMD phenotype: CFH influences the drusen of dry AMD, whereas HTRA1 influences blood vessel development, the hallmark of the wet disease type. When the two processes are combined, it leads to the composite characteristics that are seen in some cases of AMD.

Hoh, her collaborators in Hong Kong, and her colleagues at Yale including Michael Snyder and Colin Barnstable in the Departments of Molecular, Cellular and Developmental Biology and Molecu lar Biophysics and Biochemistry, and Ophthalmology, did trans-racial gene mapping by comparing genomes between precisely defined populations to find the incidence of SNP in a Chinese population—96 with AMD and 130 with normal vision.

"We found that patients with the HTRA1 SNP were 10 times more likely to have wet AMD than those without this gene variant," said Hoh. "While this is only preliminary work, it points to possible directions for future treatment of wet AMD."

Hoh also worked on a replication study led by Kang Zhang at the University of Utah School of Medicine that found a link between the same SNP and AMD. Zhang and his team studied 581 Caucasian patients with AMD and 309 with normal vision. These patients had wet AMD as well as a large amount of drusen.

To confirm the association, the Utah team also examined several donor eyes and measured the expression of the gene and the encoded protein. They found that the expressions were elevated in the eyes of patients who carry HTRA1.

"The marker we have identified is very much associated with AMD, but no one has ever pinpointed the clinical features of the gene. We need to conduct further analysis in order to understand the biological mechanisms," said Hoh.

Source-Eurekalert
SI
'"/>




Related medicine news :

1. Low Cholesterol Linked to Severe Depression and Violent Behavior in Men
2. Cough Syrup Ingredient Linked to Stroke
3. Irregular Periods Linked to Diabetes
4. Hormones Linked To Migraines
5. Triglycerides Linked To Stroke Risk
6. Smoking Linked To Low Infant Birth Weight
7. Nausea Linked To Anxiety And Depression
8. Painkiller Linked to Deaths
9. High Levels of Protein Linked to Brain Shrinkage
10. Snoring Linked To Headaches
11. Hormone Therapy Linked to Dementia
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:5/28/2016)... California (PRWEB) , ... May 28, 2016 , ... "Color ... to drag and drop a preset onto their media," said Christina Austin - CEO ... Film Studios, editors can quickly and easily add stylish color grades to their footage. ...
(Date:5/27/2016)... ... 27, 2016 , ... More than a third of American adults are considered ... surgery has received increased attention in recent years, as an article published ... weight loss, most people are familiar with the basic requirements of maintaining a healthy ...
(Date:5/27/2016)... ... May 27, 2016 , ... An influential resource amongst nurses and ... to shed lights on the variety of topics detailing why we appreciate nurses in ... why this career has gone from being in a major recession to one of ...
(Date:5/27/2016)... ... May 27, 2016 , ... ... help educate the many who are unaware of the plight of aphasia. In ... run within the “Stroke Awareness” campaign. , The link between stroke and aphasia ...
(Date:5/27/2016)... PALMYRA, Wis. (PRWEB) , ... May 27, 2016 ... ... over $90,000 in scholarships to students studying complementary medicine. Allison Outerbridge is this ... She accepted her award on May 18 at the university’s Student Leadership Awards ...
Breaking Medicine News(10 mins):
(Date:5/25/2016)... Germany and GERMANTOWN, Maryland , ... QGEN ; Frankfurt Prime Standard: QIA) today announced ... agreement with Therawis Diagnostics GmbH to develop and commercialize predictive ... and market PITX2 as a marker to predict effectiveness of ... patients. "We are pleased to partner with Therawis, ...
(Date:5/25/2016)... 25, 2016 As illustrated by ... this month, the numbers and momentum of cannabis in ... into the billions, more research and development push the ... State of Legal Marijuana Markets Report  from from ArcView ... much of the increase in sector is attributed to ...
(Date:5/25/2016)... CAMBRIDGE, England , May 25, 2016 /PRNewswire/ ... genomics company employing the precision of circulating tumour ... oncology, today announces the appointment of Professor ... will provide medical leadership across the clinical development ... that Inivata,s products help deliver significant improvements in ...
Breaking Medicine Technology: