DNAction

UK scientists say people who carry rare mutations within both copies of a gene called MUTYH are 28 times more likely to develop bowel cancer compared to the general population.

These findings, which helped validate previous discoveries, showed this risk increase only exists if mutations are in both copies of the gene. The research also adds important insights into the controversy surrounding whether or not having just one mutation raises an individual’s risk of bowel cancer.

Researchers observed those who carried biallelic mutations were more likely to develop bowel cancer when relatively young - in their 50s. Most bowel cancers, over 80 per cent, occur in people aged 60 and over. Although the contribution of biallelic mutations to the overall incidence of bowel cancer is not high, the risk of developing the disease is substantial.

Check out the entire article at Medical News Today

jwoodman News & Features bowel cancer, cancer, colon cancer, genetic testing, genetics, new research

Unfortunately, patients diagnosed with depression are often given multiple drugs before finding the right medication at the right dosage for their genetic variations. It’s only been very recently that doctors and the FDA have started using genetic testing to replace the typical trial and error methods that are prone to serious side effects, disease reoccurrence and death.

The Mayo Clinic is currently conducting a scientific study at Franciscan Skemp Healthcare in La Crosse to determine if genetic testing helps physicians in selecting the right antidepressants and dosages.

“This could be a quantum leap in psychiatry,” said Dr. Brian Proctor, a Franciscan Skemp psychiatrist who is part of the study. “I foresee genetic testing as one of the tools we will use in helping our patients.”

Josiah Allen, the study coordinator at Mayo Clinic, said the right drug could prevent death or injury and serious side effects.

“With genetic testing, it may not be necessary to try three, four or five different medications before you find the right one,” Allen said. “I think it will change the face of prescribing medication.”

In a nutshell, genetic tests can tell you whether you’re a fast or slow metabolizer. If your body uses a drug too slowly, it can cause more side effects, even toxic reactions, which severely reduces drug compliance. And when people stop taking their drugs, reoccurrence of conditions and depression can be just as debilitating.

If your body uses the drug too quickly, the drug may be eliminated from your body before it has the opportunity to produce most of its effect. Therefore a person with a faster metabolism will require a higher dose than a person with a slower metabolism.

Read the entire article in Behavioral Health Central.

jwoodman DNA Testing, Pharmacogenetics genetic testing, Pharmacogenetics

What may have been the most famous fraud in biology — Austrian biologist Paul Kammerer’s midwife toad experiments — is actually the basis for epigenetics. Epigenetics, for those unfamiliar, is a fascinating new field where genes are turned on and off based on environmental factors.

Newsweek magazine published a story online today, which will appear in the September 28 magazine issue, explaining how Kammerer was probably right. Unfortunately, he went too far to prove his case and was exposed for injecting India ink into a toad. He committed suicide six weeks later and Arthur Koestler made the saga the subject of his 1971 book, The Case of the Midwife Toad.

Check out What Alters Our Genes in the latest issue of Newsweek.

For those interested in more information on epigenetics, watch The Ghost in Your Genes, a 4-part series, from PBS’s Science NOVA.

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Keele University researchers have identified two additional genes for improving the diagnosis and treatment of breast cancer patients.

Researchers have been particularly interested in identifying and studying genes which control whether a cell lives or dies. They found survival rate for patients with a low expression of a gene known as Fau, a tumor suppressor, is twice as short as for people with normal levels. A high expression of the cancer-causing gene MELK has a similar effect.

“Our ongoing research is about finding the genes which may go wrong in people with cancer,” said Professor Gwyn Williams, who has been working on the study for 20 years. “Genetic changes give hints to where to target therapy and can also help diagnose cancer.”

The recent findings may also prove significant for ovarian and prostate cancer research.

Read the story at Science Daily.

jwoodman DNA Testing, News & Features breast cancer, new research

Sharon Ufberg, in a post for Philadelphia’s Examiner.com, takes a shot at J. Craig Venter for his lackadaisical attitude about family history. For those unfamiliar, Venter, a genomics pioneer, was recently named one of Time Magazines most influential people in the world and is one of the first humans to have his entire genome sequenced.

While we agree with Ufberg that today family history is a very important component to understanding disease risk, she entirely misses the point. The reality, as Venter tried to convey, is family history IS genetics. If we entirely understood the entire genome, we certainly wouldn’t have to look at family history. Essentially, the genes we inherit are the most accurate way to look at family history.

The reason responsible medical professionals still look at family history is because our understanding of what genetic components are responsible for complex diseases such as cancer, cardiovascular disease and diabetes is still being sorted out. While our knowledge is expanding daily and we can immediately know many drugs that we metabolize better than others, or what recessive genes we may pass to children, it’s still smart to incorporate family history knowledge with your genetic test results.

We certainly look forward to the day we can all economically have our genome fully sequenced and have a complete understanding of the genes we’ve inherited and what it means for the way we should lead our lives. In the meantime, Pathway recommends filling out your lifestyle and family history surveys as part of our overall service of providing the most accurate risk assessment known today.

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Scientists have always known that every time DNA is passed from one generation to the next, there are slight mutations. Unfortunately, the number of new mutations has been sort of an estimate until recent advancements in sequencing technologies.

A British-Chinese research team recently sequenced ten million base pairs on the Y chromosome from two men living in rural China who were distant relatives. These men had inherited the same ancestral male-only chromosome from a common relative who was born more than 200 years ago. The scientists were able to determine the slight DNA copying mistakes of the Y chromosome over the subsequent 13 generations.

By using the latest sequencing technologies, scientists were able to extrapolate their findings to the entire genome and come up with a mutation rate of one in every 30 million base pairs each time DNA is passed to the next generation.

Estimating the mutation rate with the Y chromosome is easier because most of the Y chromosome doesn’t mix with any other chromosomes. This means the mutation rate might be somewhat different on other chromosomes and we should expect to see more studies examining this fascinating aspect of humans have evolved over thousands of generations.

Read the entire story at Nature.com.

jwoodman News & Features mutation rate, new research

Traditionally chemotherapy has been the treatment of choice for those diagnosed with non-small cell lung cancer, which accounts for 80 percent of all lung cancers. Recently, however, researchers in Japan, Hong Kong and Spain have found that people with specific mutations in genes for the epidermal growth factor receptor (EGFR), can survive over twice as long by taking AstraZeneca’s target drug Iressa (gefitinib) instead of chemotherapy.

“This basically confirmed what we have thought, that in selected populations (light smokers or those who never smoked), those testing positive for EGFR mutations will do much better in progression-free survival than if you put the patient on chemo,” said Dr. Edgardo Santos, an assistant professor of medicine in the hematology and oncology section at the University of Miami’s Sylvester Comprehensive Cancer Center. “For the first time in a selected population, you have a drug which can compete with systemic chemotherapy—there is a pill that matches systemic chemotherapy.”

Read the full story at HealthNews.com.

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Everybody knows that smoking is one of the biggest risk factors for lung cancer. But what we haven’t been able to do is identify smokers that have an evern greater risk than other smokers. In other words, scientists have found more evidence that genetic differences play a big role in determining why certain smokers are much more susceptible to lung cancer.

According to more research from the UK, genes don’t just account for the risk of developing lung cancer but also the type of cancer that develops. The study, from the Institute of Cancer Research, is published in the August 15 issue of Cancer Research.

The study scanned the genomes of 1,900 people with lung cancer and compared them to those of 1,400 people without lung cancer to find differences in DNA that were linked to an increased risk of the disease. Scientists then looked for these same genetic changes in 2,000 people with lung cancer and compared them to the genomes of the same number of people without lung cancer.

Scientists also learned that people with one copy of each variant who smoke or used to smoke have a 28 per cent increased risk of developing lung cancer, whereas current or former smokers who carry both copies of each variant have an 80 per cent higher risk.

For more detail and the specific chromosome involved, read the article at Medical News Today.

jwoodman Health Care, News & Features lung cancer, new research, smoke, smoking, study

Cedars-Sinai Medical Genetics Institute, of Los Angeles, is trying to make broad-scale genetic testing more efficient by targeting ethnicity, a concept called ethnogenetics. The Institute hopes to test at least 10,000 of the 30,000 Persian Jews in Southern California.

Dr. David L. Rimoin, CSMGI director, helped pioneer genetic screening for Tay-Sachs disease in the Ashkenazi Jewish population more than 40 years ago. Since then, science has revealed many gene mutations that appear more frequently in certain ethnic groups. Recent discoveries on several mutations found in Persian Jews, plus their large numbers in Los Angeles, made this group a prime target for the launch of the program.

Every ethnic and racial group has five to 10 gene mutations that increase the risk for specific conditions, Rimoin says. Such traits are more easily identifiable — because they’re more common — in groups with a strong tradition of intermarriage.

Rimoin hopes to expand the program for Persian Jews to New York and Israel. The first 1,000 tests will be administered free, afterwards each screening will cost $200 to $300. Read the complete story for more detail in the Los Angeles Times.

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A recent study published in the June issue of the Journal of Genetic Counseling found that patients diagnosed with ocular melanoma almost unanimously wanted genetic test results related to prognosis.

The study was unusual in that it in ocular melanoma, rather than initial genetic Instead of looking at susceptibility to melanoma or using genetics to target therapies, the study looked at genetic factors related to the possibility of metastasis. Of the 99 patients diagnosed with ocular melanoma, half had undergone localized radiation to shrink the tumor. The remainder also underwent radiation, but first had cells biopsied from their tumors. These cells were grown in culture and studied for a missing copy of chromosome 3—the genetic marker most strongly linked to rapid metastatic disease.

Patients found with this marker in their tumors have at least a 50% chance of death within five years, due to swift spreading of the tumor to the liver and other organs. Aggressive cases can result in blindness and death as quickly as one year.

Even faced with the possibility of this dire prognosis, 98% of patients wanted to know. Of 99 patients, only one person indicated they’d rather not know.

Basically, people understand no good treatment currently exists after melanoma spreads and they want to know their risk for metastasis. If risk is low, it’s a huge relief. And if risk is high, it gives people an opportunity to make arrangements and get the most out of the time they have left.

Read the report in the August 11 issue of Oncology Nursing News.

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