Talk

Big news this week on new risks associated with a gene related to iron overload disease (aka hemochromatosis). A large Danish study published in the journal Neurology reports that people with certain mutations that cause hereditary hemochromatosis also have a two- to three-times risk for stroke (that’s double or triple the risk of the average joe).

Reuters summary:

Of all the various combinations of these mutations, only patients with two copies of H63D had a significantly increased risk of cerebrovascular disease and ischemic stroke, a stroke caused by a blockage in an artery in the brain, which cuts off the blood supply.

“This type of gene has previously been associated with brain diseases such as Alzheimer’s disease, Parkinson disease, ALS, multiple sclerosis, and cerebrovascular disease, but this is the first time we’ve been able to determine this gene predicts such a significant increased risk of stroke,” senior author Borge G. Nordestgaard, from Herlev University Hospital in Denmark, said in a statement. …

[T]wo copies of the H63D gene increased the risk of ischemic cerebrovascular disease by 2.1-fold and the risk of ischemic stroke by 2.8-fold. By contrast, individuals with hemochromatosis with other gene patterns did not have an increase in either of these risks.

The big question now is, how does this gene (which affects the regulation of iron at a cellular level) influence risk for stroke?

Hemochromatosis is an iron overload disease that affects around 1.5 million Americans, and probably accounts for 15 percent of the cases of adult onset diabetes. It can be caused by genes, or by non-genetic factors, or by a combination of factors. If hemochromatosis is diagnosed early, treatment can very effective and the long-term effects of iron overload can be prevented.

• More about Hemochromatosis
• Genetic testing for hemochromatosis (C282Y, H63D, S65C)

Technorati Tags: hemochromatosis, iron overload, disease, stroke, risks

My sympathies go out to Tony Snow and his family for the latest news about his colon cancer recurrence. In 2005, Snow was diagnosed with Stage 3 colon cancer, had his colon removed and underwent six months of chemotherapy. Now a second cancer has been removed, and reports say it has metastasized to his lever.

Cancer news is never good news. Snow’s news, however, is an unfortunate reminder of my “prevent colon cancer, screen screen screen!” message. (I say this to all my friends when they turn 50.)

• Colon cancer is the third cancer killer in the U.S.
• But, it is the most preventable cancer: if caught in the early stage, it’s 90% treatable.
• The way to catch colon cancer early is to screen for it: by the time someone’s showing symptoms, it’s usually progressed

The American Cancer Society and other medical organizations have recommended the following guidelines for general colorectal cancer screening:

All Men and Women Aged 50 or Older—Everyone aged 50 years or older should be tested routinely. At least 75 percent (3 out of 4) of colorectal cancers occur in people with no family or personal history and no known risk factors that would place them at high risk.

People at Increased Risk—People at increased risk may need to begin screening earlier and more often than people at average risk. Family and personal history should be considered when determining their screening schedules. People considered at high risk are:

• People with a personal or family history of colorectal cancer or polyps
• People who have had inflammatory bowel disease (ulcerative colitis or Crohn’s disease)
• People with genetic syndromes (familial adenomatous polyposis or hereditary nonpolyposis colon cancer)

Regular screening can catch colorectal cancer early, when it is most treatable. Regular screening can save lives.

How do you screen? Colonoscopy is the gold standard. Many people don’t relish this thought. There are other methods - including a stool DNA test (yes, that’s the gene connection in this post). My company’s website has a comparison chart for different screening methods.

Read more: previous posts on colon cancer screening, stool dna testing and the like

Update 3/30: Time magazine echoes the “screen, screen, screen” message.

The best way to manage colon cancer, however, is to prevent it from getting too far. … When caught early, [Dr. Raymond DuBois, incoming provost of MD Anderson Cancer Center and a colon cancer specialist] notes, malignant growths still contained in the intestine can be removed with surgery, and 50% of patients are cured this way. About 30% of colon cancer patients, however, are diagnosed with the disease after it has progressed to more advanced stages, and spread to other organs such as the liver. “The one important message for everyone is that you don’t have to go through what Tony Snow is [going through],” says DuBois.

Technorati Tags: tony snow, colon cancer, recurrence, colorectal cancer screening, screening recommendations, american cancer society, screening methods, stool DNA test

Canavan disease is one of the most common Ashkenazi Jewish genetic conditions. 1 in 40 Ashkenazi Jews are carriers of Canavan disease. As a result of this high carrier rate and the seriousness of the condition, the American College of Medical Genetics and the American College of Obstetrics and Gynecology recommend Canavan carrier screening for all Ashkenazi Jewish individuals before pregnancy. (Here’s the ACMG statement)

• Canavan disease characterized by developmental delay, a large size head, seizures, blindness, and gastrointestinal problems.
• Genetic testing is available to determine if a person is a carrier of Canavan disease. Testing can identify about 97% of Ashkenazi Jewish carriers.
• When two carriers have a child together, there is a 1 in 4 chance the child will have Canavan. (See autosomal recessive inheritance)
• 1 in 5,000 Jews have Canavan disease. (With carrier screening, it’s likely that this number is shrinking.)
• Canavan disease is caused by a deficiency of an enzyme, aspartoacylase. This enzyme is necessary for the maintenance of the myelin sheaths of nerve cells. Deficiency in the enzyme causes progressive degeneration of the central nervous system.
• No treatment is currently available for Canavan disease.
• Resources for Canavan disease: The Canavan Foundation, The Canavan Research Foundation, The United Leukodystrophy Foundation
• More posts about Ashkenazi Jewish genetic conditions

Technorati Tags: canavan disease, ashkenazi jewish diseases, carrier testing, genetic testing, genes, inheritance patterns, symptoms, treatment, resources

Take a look into genetics bloggers’ crystal ball, to see what the future might hold! Gene Genie is a blog carnival focused on genes and gene-related conditions. Here’s the latest issue at Genetics and Health: What’s In Our Genetic Future?

(Here’s the inaugural issue)

Technorati Tags: genes, genetics, blog carnival, gene genie, dieases, conditions

On Sunday, the NY Times ran an amazing interview/profile of a young woman who, at age 23, decided to be tested for Huntington’s disease: “Facing Life with a Fatal Gene.” By sharing her personal story and much more in such a large forum, Ms. Moser (the young woman) and the journalist, Amy Harmon, have brought awareness and education for HD into the public eye.

Technorati Tags: huntington’s disease, hd, genetic disease, genetic testing, pros and cons

Many people who call us about testing for genetic risks, such as thrombophilia testing, are concerned about genetic discrimination. As a result, they’re looking for ways to test anonymously and keep their test results off their medical record. How do you respond to such concerns?

I would first recommend that people become fully informed about the laws that are in place to prevent genetic discrimination. These include:

• The Health Insurance Portability and Accountability Act (HIPAA), which protects people with group health insurance from being denied insurance, having it cancelled, or having their individual rates increased based on genetic test results. HIPAA does have certain limitations, however. For example, it does not protect those who are individually insured. In addition, disability and life insurance may be impacted.

Because of the gaps in HIPAA, many states now have laws to provide additional protection. People can learn about their states’ laws on www.genome.gov. Most states have laws that:

• prevent insurers from requiring genetic tests
• prevent insurers from using genetic test results to make decisions about eligibility or rates
• apply to individual health plans as well as group health plans
• prevent disclosure of your genetic test results to third parties without your knowledge

There is also a push underway to expand federal legislation to include these elements. The Genetic Information Nondiscrimination Act (GINA) has already been unanimously approved and is undergoing debate in the House of Representatives. Approval of this law would provide expanded protection.

I find that once people understand these laws, many have less fear about testing. However, there are exceptions—including those that are individually insured. In these situations, one may consider testing anonymously, or paying for testing out of pocket, so that only he or she will have access to test results. I understand this in certain situations, but I always encourage people to think about the complexities that may arise. For example, if you find out you are positive, you may want your doctor to know, so that the best decisions about your health management can be made. If you are undergoing surgery, or are considering pregnancy for instance, it is important to let your doctor know your result, so that you can be treated accordingly. In these situations, the benefits of sharing your test result far outweigh risks of genetic discrimination, in my opinion.

On the other hand, some people may feel more comfortable testing anonymously. If they are negative (often a 50% chance), testing in this manner may provide tremendous piece of mind, and they can choose to share their negative result if they wish. Testing negative may also alleviate the need for others in the family to get tested (i.e. if there is thrombophilia in the family, but a parent tests negative, their children would not need screening (unless there is concern about thrombophilia on the other side of the family)).

In summary, individual decisions must be made when it comes to genetic testing It is important to remember that genetic tests can provide valuable and potentially life-saving information. The benefits of testing must be weighed against risks of genetic discrimination.

Liz Varga is a genetic counselor and expert on inherited blood clotting disorders. This is part II of an interview in honor of National DVT Awareness Month. Looking for more info on factor V Leiden, blood clotting disorders, or DVTs?

• Liz’ personal story and Lori’s personal story of discovering their genetic risk
• National Alliance for Thrombosis and Thrombophilia
  
• DNA Direct’s (confidential) genetic testing services for thrombophilia

Technorati Tags: genetic discrimination, genetic privacy, legislation, hipaa, gina, dvt awareness month, blood clotting disorders, thrombophilia, factor v leiden, elizabeth a. varga

To celebrate DVT Awareness Month, I asked the fabulous Elizabeth Varga for an interview. Liz has factor V Leiden, an inherited blood clotting disorder, and she has worked tirelessly to raise awareness about blood clots and thrombophilias, educating both patients and medical professionals. Liz is also a board-certified genetic counselor at Columbus Children’s Research Institute, where she also develops health promotion programs for the blood clotting disorders community.

Here is the first part of our interview. Stay tuned for more!

1. Can we talk about your personal life first? How did you learn you had factor V Leiden? How did it impact your personal and professional life?

Sure, I am always happy to share my story. My factor V Leiden story actually started with my mom. In 1999, she was traveling and hiking when her leg became painful and red. When she felt her leg, it felt like there was a large rope running down the inside of her thigh. She soon learned she had “superficial thrombophlebitis”; basically a blood clot running through the outer veins in her leg. She didn’t have to have any treatment for this, besides resting and taking pain killers. But when her doctor interviewed her, he learned that her father had had several similar episodes. It was then that he recommended testing for several clotting disorders. A couple weeks later, she learned she was heterozygous (had 1 copy) of the factor V Leiden mutation.

At the time, I was in college, so I didn’t know much about the incident. However, on a visit back home, I met with my family doctor for a checkup and she started to talk to me about the gene found in my mom. She told me that she had a colleague also had factor V Leiden. This woman had had a stroke at the age of 40; it was later learned that her colleague had a hole in her heart (called a patent foramen ovale or PFO) and that a small clot had developed in her leg veins that traveled to her brain.

My doctor also told me about birth control pills and how they could interact with factor V Leiden. She said she would recommend that I discontinue taking the pill if I tested positive. So, I decided to take the genetic test and go from there. (more…)

Familial Dysautonomia, also called FD, is a neurologic disorder characterized by episodic vomiting, abnormal sweating, pain and temperature insensitivity, an inability to produce tears, scoliosis, and abnormal feeding and sucking difficulties. This disease is found almost exclusively in Ashkenazi Jewish families.

• 1 in every 36 Ashkenazi Jews is a carrier of FD – and the disease is almost exclusively found in Ashkenazi Jewish families.
• When two carriers have a child together, there is a 1 in 4 chance the child will have Familial Dysautonomia. (See autosomal recessive inheritance)
• Genetic testing, also called “carrier screening”, is available to determine if you are a carrier of FD. This test has a detection rate of 99%.
• A single mutation on the IKBKAP gene on chromosome 9 accounts for most cases of FD.
• The only treatments available for FD treat the symptoms of the disease. Though the treatments cannot cure FD, they can improve the length and quality of a patient’s life.
• Resources for families with FD: FD Hope, National Dysautonomia Research Foundation, Dysautonomia Treatment and Evaluation Center, Dysautonomia Foundation, Inc.
• Why certain genetic conditions are found almost exclusively in certain ethnic groups: the “founder effect” and “beneficial mutation” theory.
• More posts about Ashkenazi Jewish genetic conditions

Technorati Tags: familial dysautonomia, ashkenazi jewish diseases, carrier testing, genetic testing, genes, inheritance patterns, symptoms, treatment, resources