Colleagues, the following is FYI and does not necessarily reflect my own
opinion. I have no further knowledge of the topic.
------------------------
Public release date: 16-Aug-2005
http://www.eurekalert.org/pub_releases/2005-08/uopm-gdc081605.php

Contact: Jocelyn Uhl
[log in to unmask]
phone: 412-647-3555
fax: 412-624-3184

Lisa Rossi
[log in to unmask]
phone: 412-647-3555
fax: 412-624-3184

University of Pittsburgh Medical Center

Gene's discovery could help prevent a leading cause of blindness in the 
elderly

PITTSBURGH, Aug. 16 – University of Pittsburgh researchers have 
discovered a gene linked to age-related maculopathy (ARM), the leading 
cause of untreatable blindness in the elderly. Their discovery suggests 
a simple test might be able to identify those at risk for what is 
commonly known as macular degeneration (AMD) and may lead to the 
development of more effective preventive strategies.

Researchers report that variations of a gene called PLEKHA1 are strongly 
associated with a person's risk of developing ARM. The results, a 
culmination of 15 years of research, will be published in the September 
issue of the American Journal of Human Genetics and are currently 
available online.

The discovery of the gene came about through the team's efforts to map 
the genes of 612 families affected by ARM and an additional 323 
individuals without a history of macular degeneration. Pooling data from 
a number of gene mapping studies, researchers were able to identify 
multiple locations on the chromosomes where there are common gene 
variants among people with ARM. Specifically, researchers found that a 
region on one of these chromosomes, chromosome 10, was the one most 
likely to contain a major gene that influences the risk of ARM. Further 
analysis of chromosome 10 found that a variation in PLEKHA1 to be 
strongly associated with a person's risk of developing ARM.

Earlier this year, researchers from Rockefeller University, Yale 
University, The National Eye Institute, Duke University, Vanderbilt 
University, University of Texas Southwestern, and Boston University used 
similar methods to identify the first gene variant thought to be a major 
contributor to ARM, complement factor H (CFH) on chromosome 1. The 
Pittsburgh study confirms involvement of this gene and, for the first 
time, shows that the association results also accounted for findings 
from previous genetic studies of AMD families. Importantly, the new 
study found that having both CFH and PLEKHA1 indicate a greater risk for 
macular degeneration.

"CFH was the first piece of the puzzle," said Michael Gorin, M.D., 
Ph.D., professor of ophthalmology, University of Pittsburgh School of 
Medicine, and professor of human genetics, University of Pittsburgh 
Graduate School of Public Health. "To fully understand the pathology of 
macular degeneration, we knew we needed to expand our investigation to 
find all of the genes that play a part in this condition. PLEKHA1 is an 
important second piece, and we'll keep searching for the rest of the 
pieces until we get this solved."

By identifying a number of genetic variants for ARM, researchers hope to 
use this information to develop a simple set of DNA tests to identify 
individuals who are at increased risk of this sight-robbing condition. 
Additionally, they hope to develop new preventive strategies and a 
better understanding of how ARM occurs.

An important clue to understanding the cause and mechanism of ARM was 
revealed through this discovery. PLEKHA1, like CFH, is involved in the 
cellular processes related to inflammation, which supports the 
hypothesis that damage caused by ARM is, in part, due to inflammation.

ARM is the leading cause of untreatable blindness in the elderly and 
despite recent advances in the treatment of some forms of this 
condition, it continues to be a serious threat to vision with no known 
cure. An estimated 200,000 Americans develop a severe form of AMD each 
year, making it the leading cause of blindness in people aged 65 and 
older. As many as 30 percent of individuals over the age of 75 have 
evidence of macular degenerative changes.

In addition to Dr. Gorin, contributing authors to this study are Johanna 
Jakobsdottir, graduate student in the department of biostatistics, 
Graduate School of Public Health (GSPH); Tammy Mah, department of 
ophthalmology, School of Medicine; Daniel Weeks, Ph.D., professor in the 
departments of human genetics and biostatistics, GSPH; Robert Ferrell, 
Ph.D., professor in the department of human genetics, GSPH; and Yvette 
Conley, Ph.D., assistant professor in the department of health promotion 
and development, School of Nursing, and assistant professor in the 
department of human genetics, GSPH.
###
The research was supported by a grant from the National Eye Institute of 
the National Institutes of Health, as well as by funds from Research to 
Prevent Blindness, The Eye & Ear Foundation of Pittsburgh and the Ruth 
and Milton Steinbach Foundation.
-- 
Kathrynne Holden, MS, RD < [log in to unmask] >
"Ask the Parkinson Dietitian"  http://www.parkinson.org/
"Eat well, stay well with Parkinson's disease"
"Parkinson's disease: Guidelines for Medical Nutrition Therapy"
http://www.nutritionucanlivewith.com/

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