Aug 31 2010

SNPwatch: Researchers Link Migraine Susceptibility to Genes Involved in Glutamate Regulation

Published by Shwu under SNPwatch

Headaches are a pain — literally. But while most people see them as a temporary nuisance, many others find them extremely debilitating. For the 8% of men and 17% of women who suffer from migraine headaches, these long, recurring episodes can include more than just throbbing pain: vomiting, chills, sensitivity to light or sound, or trouble concentrating are just a few of the possible symptoms. Some people experience a set of symptoms prior to their migraine attacks known as “aura” but for others the attacks come without warning.

Because the condition is complex and manifests differently in each person, the biological causes of migraine have been difficult to determine. New research, however, is implicating common genetic variants which may help to elucidate the biological underpinnings of the disease. Continue Reading »

One response so far

Aug 26 2010

SNPwatch: Researchers Identify Genetic Variants Associated with Keloids

Published by JulianaS under SNPwatch

A study published recently in the journal Nature Genetics has identified three distinct variations associated with an individual’s propensity to develop keloids.

Keloids are firm, rubbery, shiny scars that spread beyond the confines of an original wound.  They can range from pink to red or dark brown. Keloids often occur at the site of an injury, but can also occur at the site of a piercing, pimple, scratch, or even spontaneously.  The incidence of keloids is higher in females than males, and individuals with darker skin are more likely to be affected.  Throughout history and into the modern day, some cultures have used intentional keloid formation as part of rituals or as a means of decoration. Most people, however, would rather not develop keloids, as they can be disfiguring as well as painful. Continue Reading »

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Aug 20 2010

Lessons at Berkeley: Genetics and Beyond

Published by JoannaM under big questions

Having been a genetics educator for over two decades, I was excited to learn in May that Berkeley’s incoming freshman class would have an opportunity to discover whether they have an AA, AG, or GG at a specific site near the LCT gene, along with similar information for the ALDH2 and MTHFR genes.  Time and again I have seen students, friends and relatives pale at the mention of genetics concepts, until they get their own data and are instead forthcoming with questions and eager to learn. So the idea of university students learning about genetics through a small set of personal genetic data seemed an excellent one. The data would provide an opportunity for discussion of a broad range of topics, from genetics to concepts of race to the ethical issues surrounding medical genetics. And the organizers had thought long and hard about the project, developing, for instance, an online video consent form.

Last week I was deeply disappointed to learn that the course organizers, in response to a decision by the California Department of Public Health, will not be providing students with their personal genetic data. Continue Reading »

2 responses so far

Aug 17 2010

Pharmacogenetics: The Long Road From Bench To Bedside

Published by JulianaS under big questions

A patient is given a normally life saving drug and instead of getting better, gets worse.  The doctor can prove she gave the dose recommended by the manufacturer.  The manufacturer can point to clinical trials showing that this is in fact the dose that works safely for most people.  So what happened?  Who, or what, is to blame for this tragedy? In some cases, the answer lies in the patient’s DNA.

Since the beginning of the 20th century the idea of “chemical individuality,” natural differences between people in their reactions to environmental factors, including drugs, has been recognized. Since then, modern biological techniques have allowed researchers to dissect these differences and understand them at the molecular and genetic level.  But medicine has not kept pace with research, and it is the exception rather than the rule that genetics are taken into account when prescribing a medication. Continue Reading »

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Aug 11 2010

SNPwatch: When It Comes to Fighting Tuberculosis, Genetic Balance May Be the Key

Published by JulianaS under SNPwatch

NIAID

Why do some people exposed to the bacteria that causes tuberculosis (TB) get sick, while others completely resist the disease?  Research published this year in the journal Cell suggests that it all comes down to balance.

Scientists from the University of Washington used a combination of zebrafish experiments and human genetics to identify how a precisely tuned level of inflammation allows the body to fight off Mycobacterium tuberculosis, the causative agent of TB, but not go overboard. These findings not only help explain why some people are hypersensitive to TB, but may also have important implications for prevention and cure of this disease caused by a bacterium that can be found in one third of the world’s population. Continue Reading »

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Aug 09 2010

SNPwatch: Susceptibility to Bacterial Meningitis May Be Affected By Immune System Variation

Published by JulianaS under SNPwatch

When it comes to certain infectious diseases, there are some people that just get lucky.  For various reasons, they are naturally more resistant to infection or symptoms.  Often the cause is a genetic variation.  Examples include the CCR5delta32 mutation that renders about 1% of people with European ancestry resistant to some forms of HIV; the FUT2 variation that protects about 20% of people with European or African ancestry from the most common cause of the ’stomach flu’; and of course, that old genetics class stand-by, the hemoglobin mutation that causes sickle cell anemia when two copies are present, but provides protection against malaria when a person has only one copy.

Now research published this week in the journal Nature Genetics shows that a variation in an immune system gene may provide protection for some against meningococcal disease, a bacterial infection that each year affects about 2,500 people in the United States and more than 300,000 people worldwide. Continue Reading »

2 responses so far

Aug 05 2010

SNPwatch: Researchers Identify Genetic Variant That May Affect Liver Cancer Risk in Those Chronically Infected with Hepatitis B Virus

Published by AnnieM under SNPwatch

Hepatocellular Carcinoma (HCC) is the fourth most common cancer in the world.  More than half a million new cases of this form of liver cancer are reported each year.  Excessive alcohol consumption and obesity have long been linked to HCC, but the main cause of the disease is chronic hepatitis B virus (HBV) infection.  Not everyone chronically infected with the virus, however, develops HCC.

To investigate whether genetic factors play a part in whether an HBV-infected person will go on to develop HCC, researchers analyzed the DNA of several groups of people with Chinese ancestry, as it is known that in China 80% of cases of HCC are linked to chronic HBV infection.  Their results, published online this week in the journal Nature Genetics, show a strong link to a genetic variation on chromosome 1. Continue Reading »

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Aug 03 2010

What DTC Genetic Testing Can—and Can’t—Tell You

Published by 23andMe under news

This week, Mary Carmichael of Newsweek is exploring the world of direct-to-consumer (DTC) genetic testing and deciding whether or not she’d like to find out about her own DNA information.

23andMe was asked to contribute a short piece on what you can—and can’t—learn from services such as ours.  We were more than happy to help, as it is our firm belief that education is a critical first step toward our goal of meaningful integration of genetic information into clinical care.   Below is an expanded version of what we wrote.

If you’d like to join the conversation, leave a comment over at Newsweek, or follow Mary on Twitter and let her know what you think.

Get the Right Drug at the Right Dose

What we can tell you: Genetics can impact whether you’ll need more or less of a medication compared to most people, or whether you might be at increased risk for serious side effects.

For example, the blood thinner warfarin (Coumadin®) can help prevent blood clots, but it can also cause excessive bleeding in people whose sensitivity to this drug is increased by two genetic variations covered by 23andMe.   There are also genetic effects on clopidogrel (Plavix®) efficacy.  Normally this drug helps prevent heart attacks by keeping blood cells from sticking together. But a genetic variation that interferes with the drug’s metabolism prevents some people from getting the full effect, putting them at increased risk for cardiovascular events.

What we can’t do: DTC genetic testing can’t replace your doctor when it comes to making decisions about how best to treat you.  There are many factors other than genetics that need to be taken into consideration.  No one should stop taking a medication or change their dosage without a doctor’s supervision. Continue Reading »

2 responses so far

Jul 26 2010

Turning Back the Clock on Hemoglobin Production May Be Key to Sickle Cell Disease Treatment

Published by JulianaS under news

This year marks the hundredth anniversary of the description of the disease now known as sickle cell anemia.  In Ghana, an international group of scientists, public health officials, non-governmental organizations, and patients and their families met last week to talk about the current state and future of sickle cell disease. In November, another symposium will take place at the United States National Institutes of Health.

High on the priority list at these meetings are discussions about treatment for sickle cell disease – a disease that, although understood for so long, continues to bring pain and suffering to about 70,000 people in the United States and millions more worldwide.  The observation more than 60 years ago that continued production of fetal hemoglobin after birth reduces symptoms may hold the key to new treatments. Continue Reading »

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Jul 23 2010

GAO Studies Science Non-Scientifically

Published by 23andMe under big questions

As we posted here on the Spittoon yesterday, the Subcommittee on Oversight and Investigations of the House of Representatives Committee on Energy and Commerce held a hearing on “Direct-To-Consumer Genetic Testing and the Consequences to the Public Health.”

Central to this hearing was an investigation by the Government Accountability Office (GAO) into 15 DTC genetic testing companies.

The GAO refused to discuss its concerns or its report with 23andMe, and now that the report is public and we have had a chance to review it, we are troubled and find the report is deeply flawed. We note that while such an exercise as conducted by GAO has the potential to raise questions, it does not provide the answers that a more rigorous scientific study would provide.  This report raises questions, but leads to few conclusions because of its unscientific nature.  The GAO itself recognizes this, writing, “It is important to emphasize that we did not conduct a rigorous scientific study.…”

[The report is accessible from the Committee's website (Click on PDF for "Testimony of Gregory Kutz."  Gregory Kutz is Managing Director, Forensic Audits and Special Investigations, Government Accountability Office).]

We are confident in our service’s accuracy and reliability. It is widely accepted that the technology we are using is sound.  We understand that GAO did not find any problem with the underlying data that we provide – the As, Cs, Ts and Gs.  What is at question is whether or not one part of the information about that data that we provide is of value, and we believe strongly that it is.

The GAO report focused only on disease risk probabilities.  It did not focus on ancestry or the trait reports we offer.  It also failed to address that we also provide information about carrier status for single gene diseases such as cystic fibrosis and Tay-Sachs disease, as well as the fact that we provide information about a customer’s likely response to certain prescription medications that have been shown in clinical trials to have differing effects and side effects depending on a person’s genetic make-up.  This suggests that GAO found no problems with these parts of our service.

Carrier status and drug response information are clearly useful. In fact, Dr. James Evans, the Director of Adult Genetics Services at the University of North Carolina and the Editor-in-Chief of Genetics in Medicine, admitted during the Congressional hearing that drug response information would be of great interest to him as a physician.  (He was specifically referring to results pertaining to a patient’s sensitivity to the anti-viral medication abacavir.)  It should be noted that during the hearing it was not clear that Dr. Evans had been the primary consultant to GAO regarding the scientific and medical relevance of the results provided by DTC genetics testing companies.

The remarks made by 23andMe Co-Founder Anne Wojcicki and General Counsel Ashley Gould at the FDA public meeting on July 20, 2010 about laboratory developed tests demonstrate the importance of the work we are doing and our commitment to ensuring that members of the public are provided unfettered access to their DNA information in a responsible manner.  We embrace the ideas that the FDA offered today about stepping in to provide a regulatory framework and help set scientific and transparency standards across the industry.  We look forward to helping with this process.

Read on for discussion of some of the problems with the GAO report. Continue Reading »

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