Featured Research

from universities, journals, and other organizations

Genomic variant that increases risk of brain tumors discovered

Date:
August 26, 2012
Source:
Mayo Clinic
Summary:
People who carry a “G” instead of an “A” at a specific spot in their genetic code have roughly a six-fold higher risk of developing certain types of brain tumors a study has found.

People who carry a "G" instead of an "A" at a specific spot in their genetic code have roughly a six-fold higher risk of developing certain types of brain tumors, a Mayo Clinic and University of California, San Francisco study has found.

The findings, published online August 26 in the journal Nature Genetics, could help researchers identify people at risk of developing certain subtypes of gliomas which account for about 20 percent of new brain cancers diagnosed annually in the U.S. and may lead to better surveillance, diagnosis and treatment.

Researchers still have to confirm whether the spot is the source of tumors, but if it's not, "it is pretty close," says senior author Robert Jenkins, M.D., Ph.D.,a pathologist at the Mayo Clinic Cancer Center. "Based on our findings, we are already starting to think about clinical tests that can tell patients with abnormal brain scans what kind of tumor they have, just by testing their blood."

A few years ago, researchers began hunting for regions of the genome that might be associated with the development of gliomas. These groups observed a portion of chromosome 8 that contained single nucleotide polymorphisms or "SNPs" associated with brain tumors. Since then, Dr. Jenkins and Margaret Wrensch, Ph.D., professor of neurological surgery at the University of California, San Francisco, have been using a combination of sophisticated genomic techniques to search for the SNP causing brain tumors to form.

They honed in on seven candidates. One -- the SNP called rs55705857 -- confers a relative risk approaching that is seen with BRCA1, the breast cancer gene. Interestingly, this region was only found through the most laborious method used by the researchers, next generation sequencing, suggesting that experimental and mathematical shortcuts may miss such rare, highly potent gene variants, Dr. Jenkins says.

Drs. Jenkins and Wrensch found that having the "G" guanine version of this SNP -- rather than the more common "A" adenine version -- was strongly associated with slower growing gliomas.

"Being able to tell people that the mass in their brain is this type of tumor is actually good news, because it has a much better prognosis than other brain tumors," Dr. Jenkins says. "So what is it that predisposes people to develop less aggressive, but still lethal, gliomas? That makes understanding the function of this variant even more important."

As part of their work, the researchers compared the sequence of the gene variant throughout mammalian evolution and found that it has been conserved as far back as the platypus. Computer modeling indicated that the region may be a microRNA, a special kind of nucleic acid that controls the activity of genetic messages within cells. The modeling places the SNP within the functional part of the microRNA, suggesting that a change in genetic code from an A to a G could have significant consequences. The research team is investigating whether the microRNA actually exists, and what its functional implications might be.

"The altered microRNA might target tumor suppressor genes, it might activate a cancer gene, it might be involved in regulating the stability of the genome, or there might be something else going on altogether," Dr. Jenkins says. "One of the big challenges of the current genomic era is to assign functions to all these new gene variants."


Story Source:

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


Journal Reference:

  1. Robert B Jenkins, Yuanyuan Xiao, Hugues Sicotte, Paul A Decker, Thomas M Kollmeyer, Helen M Hansen, Matthew L Kosel, Shichun Zheng, Kyle M Walsh, Terri Rice, Paige Bracci, Lucie S McCoy, Ivan Smirnov, Joseph S Patoka, George Hsuang, Joe L Wiemels, Tarik Tihan, Alexander R Pico, Michael D Prados, Susan M Chang, Mitchel S Berger, Alissa A Caron, Stephanie R Fink, Chandralekha Halder, Amanda L Rynearson, Brooke L Fridley, Jan C Buckner, Brian P O'Neill, Caterina Giannini, Daniel H Lachance, John K Wiencke, Jeanette E Eckel-Passow, Margaret R Wrensch. A low-frequency variant at 8q24.21 is strongly associated with risk of oligodendroglial tumors and astrocytomas with IDH1 or IDH2 mutation. Nature Genetics, 2012; DOI: 10.1038/ng.2388

Cite This Page:

Mayo Clinic. "Genomic variant that increases risk of brain tumors discovered." ScienceDaily. ScienceDaily, 26 August 2012. <www.sciencedaily.com/releases/2012/08/120826143354.htm>.
Mayo Clinic. (2012, August 26). Genomic variant that increases risk of brain tumors discovered. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2012/08/120826143354.htm
Mayo Clinic. "Genomic variant that increases risk of brain tumors discovered." ScienceDaily. www.sciencedaily.com/releases/2012/08/120826143354.htm (accessed July 29, 2014).

Share This




More Health & Medicine News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Ebola Virus Threatens West Africa

Deadly Ebola Virus Threatens West Africa

AP (July 28, 2014) West African nations and international health organizations are working to contain the largest Ebola outbreak in history. It's one of the deadliest diseases known to man, but the CDC says it's unlikely to spread in the U.S. (July 28) Video provided by AP
Powered by NewsLook.com
$15B Deal on Vets' Health Care Reached

$15B Deal on Vets' Health Care Reached

AP (July 28, 2014) A bipartisan deal to improve veterans health care would authorize at least $15 billion in emergency spending to fix a veterans program scandalized by long patient wait times and falsified records. (July 28) Video provided by AP
Powered by NewsLook.com
Two Americans Contract Ebola in Liberia

Two Americans Contract Ebola in Liberia

Reuters - US Online Video (July 28, 2014) Two American aid workers in Liberia test positive for Ebola while working to combat the deadliest outbreak of the virus ever. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) 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:
from the past week

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