DNA and Disease

New Gene for Ovarian Cancer – BNC2

by Dr. Hsien-Hsien Lei
Posted August 5, 2009 in DNA and Disease

Infamous genes for breast and ovarian cancer, BRCA1 and BRCA2, now have a new companion – BNC2. A new study has found that BNC2 is more common than BRCA1 and BRCA2 but does not confer as high of a risk for ovarian cancer. (Wall Street Journal)

As reported in Nature Genetics, researchers performed a genome-wide association study and identified a new ovarian cancer susceptibility locus on chromosome 9p22.2 where the BNC2 gene is located. The gene may encode a transcription factor that plays a role in the differentiation of spermatozoa and oocytes.

Carolyn B Saks award-cropped In September 2007, I interviewed two women who’d experienced ovarian cancer – Sandi Pniauskas and Carolyn Benivegna. Sadly, Carolyn died a year later but Sandi carries on her work to bring awareness to ovarian cancer. She is urging people to sign the petition for an ovarian cancer awareness postage stamp in memory of Carolyn.

We, the undersigned, respectfully request that the Citizens’ Stamp Advisory Committee approve an Ovarian Cancer Awareness Stamp. With early diagnosis and specialized care, survival rates increase dramatically. Every day counts…women/girls of all ages are dying needlessly from this terrible disease. Each year, more than 20,000 American women are diagnosed with ovarian cancer and nearly 16,000 deaths occur in the U.S. from this dreaded disease. Ovarian cancer is the deadliest of all gynecologic cancers, killing more women than all other gynecologic cancers combined. Every female is at risk (even those who have had their ovaries removed), and no age is spared (girls as young as one year old have been diagnosed with Ovarian Cancer).

For more information, see the National Cancer Institute’s page on ovarian cancer.

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Overweight Parents, Overweight Children

by Dr. Hsien-Hsien Lei
Posted July 14, 2009 in DNA and Disease

image Seems like I’m stating the obvious, doesn’t it? Of course parents have a huge impact on whether their children become overweight. They buy whatever food is in the home and model eating habits. These preferences, however, are most likely partly genetic and partly behavioral.

In David Kessler’s new book, The End of Overeating, he discusses how serotonin and dopamine work to increase our cravings and appetite. Both genes and conditioning contribute to the levels of these neurotransmitters in our brain.

The interaction between genes and behavior is difficult to tease apart. A recent study has found that the behaviors of obese parents may be more to blame than the genes they’ve passed on to their children.

The EarlyBird Diabetes Study looked at 226 British families and found that :

  • Obese mothers are 10 times more likely to have obese daughters
  • Obese fathers are 6 times more likely to have obese sons
  • There is no association between obese mothers and obese sons, obese fathers and obese daughters

The Study’s Director, Professor Terry Wilkin said:

Any genetic link between obese parents and their children would be indiscriminate of gender. The clearly defined gender-assortative pattern which our research has uncovered is an exciting one because it points towards behavioural factors at work in childhood obesity.

But don’t count out genetics! What about imprinting? Genomic imprinting results in exactly this sort of pattern in which genes are expressed differently depending on the parent of origin, mother or father.

Regardless, there is no question that obesity rates in developed countries have increased tremendously. In The End of of Overeating, Dr. Kessler makes the case that it’s because the food industry knows exactly how to alter food chemistry and layer fat, sugar, and salt to make food super-palatable. So even though our genes may not have changed that much in the last half century, the foods that we have ready access to certainly have. Just think what life must have been like before McDonald’s was founded in 1940!

In our family the pattern observed in the study seems to be holding true. My son takes after his svelte father while my daughter tends towards the chubbier side. Considering I am feeding them all, I suggest that genes and how they influence what and how much we eat are still important. That doesn’t excuse my tendency to indulge, though. As with everything to do with parenting, time to reconsider what kind of example I’m setting for my kids.

News.com.au, ScienceDaily

Edited 28 Jul 2009 to clear up misstatement about imprinting.

(2 comments)


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Preimplantation Genetic Diagnosis (PGD): A Discussion

by Dr. Hsien-Hsien Lei
Posted November 6, 2008 in DNA and Disease

This past April, I participated in a vodcast with Dr. Chris Korey of the College of Charleston and students in his Molecular Biology Lab. We talked about the science and ethics behind direct-to-consumer genetic testing. While I’m not too pleased with the way I looked while heavily pregnant (eek!), we had a great conversation and I was impressed with the students’ enthusiasm and thoughtfulness.

This month, Dr. Misha Angrist is the guest participant and he’s hosting a discussion on preimplantation genetic diagnosis (PGD), selection and disability on his blog, Genomeboy. I hope you’ll join the students in conversation there.

For more information on PGD, please see these previous posts here at Eye on DNA:

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Family History of Disease Scares Parents More Than Genetic Test Results

by Dr. Hsien-Hsien Lei
Posted November 6, 2008 in DNA Testing, DNA and Disease

image Should parents purchase direct-to-consumer genetic tests for their under-age children? Joanna Mountain, Senior Director of Research at 23andMe, chose to do so for her two sons and found it to be a positive experience overall (of course!). I have not done so for my two children and haven’t even done so for myself. Just call me chicken.

In a timely study published in the November issue of the Archives of Pediatrics & Adolescent Medicine, researchers at the University of Michigan CS Mott Children’s Hospital staged a hypothetical situation and randomized over 1,300 parents to receive hypothetical genetic risk assessments framed as family history or genetic test results. They found that parents were actually more worried if they had observable, tangible evidence of a family history of disease than if the results were purely based on genetic tests.

So it seems that nothing strikes fear into our hearts more than knowing that a family member is ill and that we may also have inherited an increased susceptibility to the illness. While genes may be floating around in our consciousness, they remain an abstract concept that most of us are not able to include in our daily risk analyses.

NB: Daniel MacArthur at Genetic Future has more on genome scans for the whole family although he considers it mainly from a business perspective than from one as a parents since he isn’t one yet.

via Los Angeles Times

Photo credit: Wellcome Images

(3 comments)


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Bioethicist Arthur Caplan Says Corporate Greed Drives Genetic Testing Marketplace

by Dr. Hsien-Hsien Lei
Posted October 15, 2008 in DNA Testing, DNA and Disease

price tag Fresh on the heels of the launch of the deCODE BreastCancer genetic test last week, Dr. Arthur Caplan, renowned director of the University of Pennsylvania Center for Bioethics, said in an article for MSNBC.com that breast cancer gene tests are not worth the price.

If you are worried about your risk of getting the disease, or are thinking about getting a genetic test done for any other reason, talk with your doctor or a genetic counselor who can determine whether your family history justifies the expense. You may be surprised to find that you can make changes in lifestyle and monitoring your own health that can reduce your risk without testing.

Dr. Caplan even goes so far as to accuse genetic testing companies of corporate greed which, given the current economic environment in the U.S., is bound to send shivers down their spine.

With respect to deCODE’s breast cancer genetic test, it examines seven single nucleotide polymorphisms* (SNPs) that are purportedly involved in 60 percent of all breast cancers. Results from the test are given as personal lifetime relatively risk compared to the general population (specifically people of European descent). Other risk factors such as family history, pregnancy history, etc. are not taken into consideration when calculating a deCODE BreastCancer genetic test taker’s risk.

deCODE’s Chief Scientific Officer, Dr. Jeff Gulcher, responded to Dr. Caplan on its blog, deCODE You (a member of the DNA Network) and drew analogies between the BreastCancer genetic test and LDL-cholesterol tests. Anyone who is identified to be at higher risk of breast cancer (or in the analogy, high cholesterol leading to cardiovascular disease) would benefit from greater vigilance, more intensive screening, and possibly, preventive therapy.

Another DNA Network member, Dr. Steve Murphy at Gene Sherpas calls the deCODE BreastCancer test “hype.” Cancer Research UK also believes that “it’s too early for a test of this kind to be released to the general public.” Dr. Len Lichtenfeld of the American Cancer Society does not believe the test will “advance our cause in the fight to reduce deaths from cancer in a meaningful, evidence-based and scientifically accurate way.”

Speaking of cost, though,it seems that 23andMe customers get the better deal because all of the six of the seven SNPs (rs4415084 was on the v1 chip but not on the v2 chip) examined in the deCODE BreastCancer genetic test are included on version 2 of the 23andMe gene chip (I checked using SNPedia) not to mention the other nearly 600,000 SNPs included in the 23andMe report. A 23andMe DNA test costs $399 while a deCODE BreastCancer genetic test costs $1,625.

deCODE’s test offers other bits and fancy algorithms for calculating risk to justify the price. But customers should be aware that there is more than one way to get the genetic data they desire. And that data’s worth can be hard to price.

*See the list of SNPs in this sample report (pdf).

via Al’s Morning Meeting at Poynter Online

NB: I am a consultant to DNA Direct, a genetic testing company.

Photo Credit: abbyladybug

*Thanks to Mike Cariaso of SNPedia for clarifying what’s on the 23andMe chips.

(5 comments)


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Chromosome 20 Involved in Male Pattern Baldness

by Dr. Hsien-Hsien Lei
Posted October 13, 2008 in DNA Testing, DNA and Disease

Evil doll by Helge CarlsenConsumers of genetic testing can now get more information on male pattern baldness from chromosome 20. A genetic test specific for hair loss is already on the market – HairDX. It examines CAG repeats in the androgen receptor gene (AR) on the X chromosome. According to Technology Review, in one study of 2,000 balding men and women, 1 in 7 Caucasian men had markers on both chromosome 20 and the X chromosome that increased their risk of baldness.

Lest you think baldness is a purely cosmetic concern, there is a link between male pattern baldness and increased risk of cardiovascular disease and insulin resistance. In 2000, the Physicians’ Health Study found that “vertex pattern baldness is a marker for increased risk of coronary heart disease events, especially among men with hypertension or high cholesterol levels.”

Interestingly, the HairDX website makes no mention of the link between hair loss and heart disease. Perhaps because they don’t want to run into trouble for making any innuendos about the medical utility of their DNA test. However, with this bit of information in mind, I’m less likely to make jokes at their expense.

Photo credit: Helge Carlsen

(5 comments)


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My Son, The Genetic Epidemiologist

by Dr. Hsien-Hsien Lei
Posted September 16, 2008 in DNA Fun, DNA and Disease

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My six-year-old’s reading and mark-up (in purple) of a paper in Nature Genetics authored by my friend, Dr. Linda Kao.

Press Release – New gene variant identified for nondiabetic end stage renal disease in African-Americans

Scientists at Johns Hopkins schools of Public Health and Medicine have, for the first time, identified variants in the gene MYH9 that are associated with increased risk for non-diabetic end stage renal disease (ESRD,) which is the near-loss of kidney function leading to either dialysis of transplant. MYH9, located on the 22 chromosome, is the first gene identified for common forms of kidney disease. The study was published online September 14 in the journal Nature Genetics and will be published in the October print edition. In a separate study published in the same issue, researchers at the National Institutes of Health reported similar findings.

(5 comments)


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Helix Health Genomic Medicine Webcast

by Dr. Hsien-Hsien Lei
Posted May 20, 2008 in DNA and Disease

pretty is what changesWhoa! Almost missed it.

Fellow DNA Network member, Dr. Steven Murphy, and his company, Helix Health, will be hosting a webcast tomorrow, May 21, 2008 at 1:00 pm EDT.

How Genomic Medicine Is Changing the Management of Breast & Ovarian Cancer

Registration is free and will feature Jessica Queller, author of Pretty is What Changes: Impossible Choices, The Breast Cancer Gene and How I Defied My Destiny.

(1 comment)


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23andMe Collaborates on Study of Parkinson’s Disease Genetics

by Dr. Hsien-Hsien Lei
Posted May 15, 2008 in DNA and Disease

Researchers are rarely study participants. Up until last week, I’d only had a hand in designing and conducting epidemiologic studies and no experience at all participating in one. While waiting for my prenatal check-up, a master’s degree student at Imperial College recruited me for her thesis study on stress and comorbidity in pregnant women. I was happy to help out since I know firsthand how hard recruiting can be especially since she told me she’d had to reduce her sample size from 200 to 100 because it was such tough going.

All I had to do was check the boxes on about 10 pages of questions and collect a total of six saliva samples over two days. Two samples are taken upon waking and another around 9 pm. I’m sorry to say that on the first day, I forgot that I was supposed to sit still while the cotton plug was under my tongue for two minutes absorbing saliva and I also forgot to take my night-time sample at 9 and did it at 10:30 instead. I was also supposed to mail my frozen samples in by regular mail this past Monday or Tuesday but got distracted so it will have to wait until next week.

What a lousy study participant I am especially given that I know what it’s like to be on the other side!

Perhaps 23andMe and the Parkinson’s Institute and Clinical Center will have more compliant study participants. They are planning a Web-based study of Parkinson’s disease that will ask 150 people to donate their saliva for genetic analysis like any 23andMe customer as well as submit personal data via the Web. In addition, the study will validate the online data collection method with face-to-face or phone interviews.

The San Francisco Chronicle reports that 23andMe also hopes that pharmaceutical companies will pay them for access to personal genomics customers who have specific conditions or disorders. Linda Avey is quoted as saying the pharmaceutical companies would be contacting customers to offer them the opportunity to participate in clinical trials (where 23andMe may also be able to offer database services) but I can easily see this extending into personalized ads for personalized medicine. Could be both good and bad.

From my recent and previous personal experiences, interviewer-led data collection will always be the gold standard because participants can ask for clarification on sample collection instructions and questions. However, post boxbeing able to complete questionnaires in the comfort of one’s own home without time pressure (I was in a rush in case I was called in for my appointment), may increase the accuracy of the data being collected. The 23andMe Parkinson’s disease study will be valuable not only for its potential genetic discoveries, but also for its insights into the implementation of the Web in scientific research. Unfortunately, there’s no easy way for me to spit my sample into them series of Internets tubes so I guess I’ll still have to remember to schlep them to the mailbox on Monday.

Photo credit: David Wilmot on Flickr

(2 comments)


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DNA Podcast: Genetic Testing and Adolescents

by Dr. Hsien-Hsien Lei
Posted April 5, 2008 in DNA Podcasts and Videos, DNA Testing, DNA and Disease


powered by ODEO

In this Melbourne University Up Close podcast, Dr. Shane Huntington interviews Dr. Rony Duncan of the Murdoch Children’s Research institute about genetic testing and adolescents. A full transcript is also available.

If we allow young people to have that information about their future, or if we allow parents to test their children and obtain that information, what happens if those children grow up and decide that they don’t want the information and decide that they didn’t actually make an informed choice?

Also see my previous post – American Journal of Medical Genetics Special Issue on Children and Genetics.

via ScienceAlert

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