Navigation Links
Genetic test results for Lynch syndrome improved with new computer program
Date:11/1/2012

SALT LAKE CITYMany patients who have genetic testing for Lynch syndrome, a hereditary predisposition to colon cancer, receive the inconclusive result "variants of uncertain clinical significance." This can be a problem, as people with Lynch syndrome have a much higher probability to develop colon cancer, and often develop colon cancer at an earlier age than is common among the general population; consequently, they need to begin screening at a much younger age.

Now, between two-thirds and three-fourths of these genetic variants can be classified into categories that indicate the most appropriate screening and treatment guidelines, according to two complementary papers published in this month's Human Mutation Early View e-publication. The two papers, both co-authored by Sean Tavtigian, Ph.D., a Huntsman Cancer Institute (HCI) investigator and associate professor in the Department of Oncological Sciences at the University of Utah, provide a model that could help physicians as they assess their patient's risk to develop cancer.

According to the American Cancer Society, about 143,460 new cases of colon cancer will be diagnosed in the United States this year. The National Cancer Institute estimates that two to four percent of all colon cancer is attributable to Lynch syndrome.

Mutations in mismatch repair genes, which proofread DNA to correct genetic typos that occur during the replication process, are known to be the cause of the syndrome. "Some people in families with Lynch syndrome have already known mutations, and a small number of missense substitutions have also been classified as pathogenic," said Tavtigian. "But a fair number have other missense substitutions for which the clinical significance could not be determined, creating uncertainty concerning proper screening and treatment for patients and physicians alike."

The first of the two studies reported on standardizing several already available computer programs that grade the severity of missense substitutions (at the genomic level, these mutations affect only a single structural unit of DNA rather than an entire gene; at the protein level, they affect only a single amino acid rather than the entire protein). The second describes how clinical data concerning the tumors, family history, and other factors were combined with that initial information about severity. Taken together, the procedures described in the two papers allow previously unclassified genetic variations to be assessed for the level of risk they pose in colon cancer development.

"Using these tools, we can evaluate any particular missense substitution and come up with a percentage indicating the probability that it is pathogenic," said Tavtigian. "I'm very careful to avoid saying pathogenic or neutral as an either-or statement. With missense substitutions, I don't believe in a binary classification." A scale developed by his team in 2008 indicates the appropriate level of clinical action for a given percentage of risk, he adds.

Tavtigian is senior author on the first study. Amanda B. Spurdle, Ph.D., associate professor of molecular cancer epidemiology at the Queensland Institute of Medical Research, Brisbane, Australia, is senior author of the second paper, and Tavtigian is a co-principal investigator.

As a result of this research, HCI now has a Web site that physicians, researchers, and even the public can use to look up the probability that a missense substitution in any of the four colon cancer mismatch repair genes is pathogenic. In the future, HCI plans to develop a "suite of Web sites dedicated to unclassified variants in many clinically important cancer susceptibility genes," according to Tavtigian.


'/>"/>

Contact: Linda Aagard
801-587-7639
University of Utah Health Sciences
Source:Eurekalert

Related medicine news :

1. IU researchers report first effective treatment of tumors arising from common genetic disease NF1
2. Smoking and hyperactivity share common genetic risk factor
3. Moffitt Researchers find genetic predictors of fatigue for some prostate cancer patients
4. CWRUs Maxwell J. Mehlmans book examines issues emerging in genetic engineering
5. Genetically-engineered preclinical models predict pharmacodynamic response
6. Scientists Map Genetic Blueprint of Heart
7. Epigenetics emerges powerfully as a clinical tool
8. Parents of babies with sickle cell trait are less likely to receive genetic counseling, study says
9. How genetics shape our addictions
10. Researchers find first evidence for a genetic cause for Barretts esophagus
11. Genetics Society of Americas Genetics journal highlights for September 2012
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/27/2017)... ... March 27, 2017 , ... From 1999 to ... responsible for over 33,000 of the 52,404 drug-related deaths in 2015.(2) To combat ... which proposes a tax on prescription opioids to fund drug rehabilitation and prevention ...
(Date:3/25/2017)... PA (PRWEB) , ... March 25, 2017 , ... Getting ... as a public relations partner. , All through the year, Garden Media aims ... press releases, working with key influencers and pitching client’s key messages to ...
(Date:3/24/2017)... (PRWEB) , ... March 24, 2017 , ... ... Infection,” which will spark a conversation on the current obstacles facing infection prevention ... of completely preventable deaths caused by these infections. , The print component ...
(Date:3/24/2017)... ... 2017 , ... According to a new study by NCPA Senior Fellow John ... the rules Congress has directed the CBO to follow. The CBO itself previously recognized ... Yet, it estimates a reduction in employer-based coverage due to the GOP reform, which ...
(Date:3/24/2017)... Sedona, Arizona (PRWEB) , ... March 24, 2017 ... ... Shamangelic Healing Center, Sedona, Arizona’s Premier Center for Shamanic Healing and Spiritual Awakening, ... Jorge Luis Delgado, June 9--24, 2017. This sacred and spiritual journey during ...
Breaking Medicine News(10 mins):
(Date:3/24/2017)... 24, 2017 FinancialBuzz.com News Commentary  ... According to ... cannabis market research, the legal cannabis market is projected to ... despite conflicting signals from the current presidential administration. The report ... two biggest drivers of growth in this industry are the ...
(Date:3/24/2017)... Mar 24, 2017 Research and Markets has ... and Diagnostics, 2017 - 2035" report to their offering. ... The Deep Learning: Drug ... future outlook of the growing market of deep learning solutions within ... learning algorithms have emerged as a novel solution to generate relevant ...
(Date:3/24/2017)... YORK , March 24, 2017 ... and Equipment stocks, which are: Neovasc Inc. (NASDAQ: NVCN), Hologic ... Heart Inc. (NASDAQ: SSH ). These companies are ... its prior gains on Thursday, March 23 rd , 2017, ... afternoon, while shares of health care companies in the S&P ...
Breaking Medicine Technology: