Featured Research

from universities, journals, and other organizations

New urine test could diagnose eye disease

Date:
October 8, 2013
Source:
Duke University
Summary:
You might not think to look to a urine test to diagnose an eye disease. But a new study says it can link what is in a patient's urine to gene mutations that cause retinitis pigmentosa, an inherited, degenerative disease that results in severe vision impairment and often blindness.

A composite image of the human retina shows diffused pigmentary retinal degeneration.
Credit: Ziqiang Guan, Duke University Medical Center

You might not think to look to a urine test to diagnose an eye disease.

But a new Duke University study says it can link what is in a patient's urine to gene mutations that cause retinitis pigmentosa, or RP, an inherited, degenerative disease that results in severe vision impairment and often blindness. The findings appear online in the Journal of Lipid Research.

"My collaborators, Dr. Rong Wen and Dr. Byron Lam at the Bascom Palmer Eye Institute in Florida first sought my expertise in mass spectrometry to analyze cells cultured from a family in which three out of the four siblings suffer from RP," said Ziqiang Guan, an associate research professor of biochemistry in the Duke University Medical School and a contributing author of the study.

Guan's collaborators had previously sequenced the genome of this family and found that the children with RP carry two copies of a mutation at the dehydrodolichol diphosphate synthase (DHDDS) gene, which makes the enzyme that synthesizes organic compounds called dolichols. In humans, dolichol-19, containing 19 isoprene units, is the most abundant species.

The DHDDS mutation, which was found in 2011, is the latest addition to more than 60 gene mutations that have been implicated in RP. This mutation appears to be prevalent in RP patients of the Ashkenazi Jewish origin, and 1 in 322 Ashkenazi carries one copy of the mutation.

"I knew from my previous experience in analyzing urine samples from liver disease patients that I can readily detect dolichols by liquid chromatography and mass spectrometry," Guan said. Using these techniques, he analyzed urine and blood samples from the six family members and found that instead of dolichol-19, the profiles from the three siblings with RP showed dolichol-18 as the dominant species. The parents, who each carry one copy of the mutated DHDDS gene, showed intermediate levels of dolichol-19 and higher levels of dolichol-18 than their healthy child. Guan believes dolichol profiling could effectively distinguish RP caused by DHDDS mutation from that caused by other mutations.

Guan and his collaborators hope to develop the dolichol profiling method as a first-line diagnostic test to identify RP patients with abnormal dolichol metabolism. They think this mass spectrometry-based detection method will help physicians provide more personalized care to RP patients, especially to young children whose retinal degeneration has not fully developed.

"Since the urine samples gave us more distinct profiles than the blood samples, we think that urine is a better clinical material for dolichol profiling," he said. Urine collection is also easier than a blood draw and the samples can be conveniently stored with a preservative. The team is now pursuing a patent for this newl diagnostic test for the DHDDS mutation.

There are currently no treatments for RP, but Guan hopes his research will shed light on potential drug design strategies for treating RP caused by DHDDS mutation. "We are now researching ways to manipulate the dolichol synthesis pathway in RP patients with the DHDDS mutation so that the mutated enzyme can still produce enough dolichol-19, which we believe may be important for the rapid renewal of retinal tissue in a healthy individual."


Story Source:

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


Journal Reference:

  1. R. Wen, B. L. Lam, Z. Guan. Aberrant dolichol chain lengths as biomarkers for retinitis pigmentosa caused by impaired dolichol biosynthesis. The Journal of Lipid Research, 2013; DOI: 10.1194/jlr.M043232

Cite This Page:

Duke University. "New urine test could diagnose eye disease." ScienceDaily. ScienceDaily, 8 October 2013. <www.sciencedaily.com/releases/2013/10/131008152225.htm>.
Duke University. (2013, October 8). New urine test could diagnose eye disease. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2013/10/131008152225.htm
Duke University. "New urine test could diagnose eye disease." ScienceDaily. www.sciencedaily.com/releases/2013/10/131008152225.htm (accessed October 1, 2014).

Share This



More Health & Medicine News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Cases Keep Coming for Monrovia's Island Hospital

Ebola Cases Keep Coming for Monrovia's Island Hospital

AFP (Oct. 1, 2014) A look inside Monrovia's Island Hospital, a key treatment centre in the fight against Ebola in Liberia's capital city. Duration: 00:34 Video provided by AFP
Powered by NewsLook.com
Ebola Puts Stress on Liberian Health Workers

Ebola Puts Stress on Liberian Health Workers

AP (Oct. 1, 2014) The Ebola outbreak is putting stress on first responders in Liberia. Ambulance drivers say they are struggling with chronic shortages of safety equipment and patients who don't want to go to the hospital. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Doctors Reassure Public Ebola Patient Won't Cause Outbreak

Doctors Reassure Public Ebola Patient Won't Cause Outbreak

Newsy (Sep. 30, 2014) After the announcement that the first U.S. patient had been diagnosed with Ebola, doctors were quick to say a U.S. outbreak is highly unlikely. Video provided by Newsy
Powered by NewsLook.com
TX Hospital Confirms Patient Admitted With Ebola

TX Hospital Confirms Patient Admitted With Ebola

AP (Sep. 30, 2014) Medical officials from Texas Health Presbyterian Hospital confirm they are treating a patient with the Ebola virus, the first case found in the US. (Sept. 30 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