The findings provide a better understanding of the spread and prevalence of the American Founder Mutation, a common cause in North America of Lynch syndrome, a hereditary cancer syndrome that greatly increases a person’s risk for developing cancers of the colon, uterus and ovaries.
The same investigators discovered the mutation in 2003. That research identified nine families with the mutation and concluded that a German immigrant couple brought the mutation to North America in 1727.
The latest study includes an additional 32 families and indicates that the mutation is actually about 500 years old, suggesting that it arose several generations earlier in Europeans or perhaps in Native Americans.
Of the 41 families overall, most are clustered in Kentucky, Ohio and Texas.
Scientists at the Ohio State University Comprehensive Cancer Center and Creighton University conducted the study, published recently in the journal Cancer Research.
“The increased age of the American Founder Mutation means that it is significantly more prevalent in the United States than previously thought,” says principal investigator Albert de la Chapelle, a researcher with Ohio State’s Human Cancer Genetics program.
“Of interest is that this mutation has not been found in Europe, which is tentative evidence, along with hints from family histories, that it may have arisen in a Native American.”
The new study estimates that the mutation is present in 32,150 Americans as compared with the earlier figure of 18,981. “But these numbers are theoretical and need to be substantiated by further work,” de la Chapelle notes.
“This is an important public health concern,” de la Chapelle says, “because individuals with a Lynch syndrome mutation can benefit from earlier and more frequent cancer surveillance.”
In addition, he says, a simple, cheap genetic test can detect the mutation.
Lynch syndrome, also known as hereditary nonpolyposis colon cancer, is responsible for about one third of hereditary colon cancers, and almost 3 percent of colon cancer generally, or about 4,500 cases annually in the United States.
The initial study of nine families showed that the American Founder Mutation results in the loss of a very specific piece of a gene called MSH2 (although many other mutations also cause Lynch syndrome).
The new study linked 27 of the 41 families into seven groups through genealogic studies.
The age of the mutation was estimated using certain markers along the DNA located at either end of the mutation. Such patterns of markers are called haplotypes.
When a new person was identified for the study, the DNA on each side of the individual’s mutation was tested for the markers, producing a shared haplotype. The shorter the shared haplotype, the older the mutation. This information led to the estimated age of 500 years.
“This data pushed the original founder mutation back to around 1500, plus or minus a number of years,” says coauthor Heather Hampel, a genetics counselor and researcher with Ohio State’s Human Cancer Genetics Program.
“The Pilgrims began arriving in the 1600s, so the mutation could have arisen first in very early settlers from Europe, or in Native Americans.”
“It’s unclear whether we’ll ever learn who the first person was to have this mutation,” Hampel says, “but it is clear that the mutation is much older than we thought and probably more widespread. For that reason, we feel it is potentially a serious public health issue, particularly in states such as Kentucky, Ohio and Texas where it is very prevalent.”
Darrell E. Ward | EurekAlert!
The importance of biodiversity in forests could increase due to climate change
17.11.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig
Win-win strategies for climate and food security
02.10.2017 | International Institute for Applied Systems Analysis (IIASA)
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
21.11.2017 | Physics and Astronomy
21.11.2017 | Materials Sciences
21.11.2017 | Health and Medicine