DNA Testing

Genetics = Real Science

by Dr. Hsien-Hsien Lei
Posted November 14, 2009 in DNA Testing

Matchmaking services are adding DNA testing to their list of offers. The DNA test analyzes HLA genes of the immune system that influence a person’s body odor. The theory is that people are attracted to those whose HLA genes and body odor differ from their own so that their potential offspring have the possibility of inheriting a more varied set of HLA genes leading to enhanced health due to a stronger immune system.

In an Associated Press article, Dr. Rocio Moran, medical director of the General Genetics Clinic at the Cleveland Clinic said:

They are just trying to make a buck. That if it’s genetic, it must be real science.

That’s the kind of argument some shady companies are making about direct-to-consumer genetic testing. It reminds me of the ruckus earlier this year over companies that offer genetic testing to parents who’re interested in having their children tested for athletic prowess and other abilities.

If it’s genetic, it must be real science.

If it’s science, it must be true.

Le Creuset Enameled Cast-Iron 2-Quart Heart Casserole, RedAnyone living in the real world knows that genetics and science can only carry you so far. In the end, what it comes down to is the kind of person you are in spite of your genes. That doesn’t mean a genetic test is worthless. If you’re the kind of person that thinks a DNA test holds some kind of magic then maybe you will be able to find a mate who thinks the same way. After all, there’s a lid for every pot.

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Knowledge about Genetic Risk is Power or is it Fear?

by Dr. Hsien-Hsien Lei
Posted November 2, 2009 in DNA Testing

IMG_2137 A little over two years ago, I confessed that I was “just a little scared of genetic testing.” I have two young children and almost every day I see traits in them that I’m pretty sure they inherited from me whether via genes or behavior. If you’re a parent, I’m sure you can imagine that there’s a lot of self-blame going on in our house.

So when it comes to genetic testing, I should want to know but I don’t. At least not right this minute. Haven’t I got enough to worry about?

From Middletown Journal’s month-long series on the battle against cancer – Many with cancer gene don’t want to know.

There are people out there who may not want to know. There’s a subset of people who if they knew would act on the information and benefit and there are others who would rather bury their heads in the sand.

~Dr. Michael Watson, director of the American College of Medical Genetics

NIH Director Francis Collins, however, falls squarely in the camp of those who not only want to know, they act on the info. Well done!

Collins hits the gym following genetic testing from The Great Beyond, Nature blog

Maybe if a genetic test could motivate me to go to the gym and lose weight, it would be worth it.

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Dr. Robert Marion on Direct-to-Consumer Genetic Testing

by Dr. Hsien-Hsien Lei
Posted August 26, 2009 in Books About DNA, DNA Testing, Personalities with DNA

genetic rounds robert marion

My interview with clinical geneticist and author Dr. Robert Marion continues today with his thoughts on direct-to-consumer genetic tests and genome scans.

In the past couple of years, genetic testing companies like 23andMe have begun offering genome scans to the general public. Have you purchased direct-to-consumer genetic tests such as these? Would you recommend it to anyone even for purely recreational reasons? Why or why not?

The age of personal health through genetic testing is clearly upon us, and this is definitely a good thing.  However, genetic information is a powerful tool, and it must be used carefully.  In the past, experiences with presymptomatic testing for Huntington disease and BRCA 1 and BRCA2 mutations have made all of us aware of the potential problems related to providing genetic testing without supplying adequate pre- and post-test genetic counseling.

And this is the heart of the problem with direct-to-consumer genetic testing; without careful explanation, without accompanying genetic counseling to explain their meaning, the results are not only meaningless, they can actually be harmful. 

Traditionally, this has always been a problem with genetic testing: the technology, our ability to perform the testing, has always run way ahead of our ability to deal with the consequences of that testing, educationally, morally and ethically.  If a test is performed, who should have access to the results?  Should employers be allowed to see them?  Should health and life insurance carriers? And who should pay for these tests?  If insurance companies cover the cost, shouldn’t they be allowed to see the results (and make decisions about coverage based on those results)?

Mercifully, the passage of GINA (The Genetic Information Non-Discrimination Act of 2008) has prevented the latter from occurring, but all of this needs to be worked out and rules put in place before testing is provided, not after.


For those of you who have purchased a direct-to-consumer genetic test, PhD candidate Sudeepa Abeysinghe at Australian National University is recruiting research participants. She says:

My research is being conducted completely independently of any testing company.  It focuses upon the consumer experience, and I do not ask any potentially sensitive questions about specific genetic results. 

The survey can be found on the (secure) Australian National University website at this address:  https://apollo.anu.edu.au/default.asp?pid=3937

Please help out if you can!


For more on Dr. Robert Marion and his new book, Genetic Rounds:

(>> Start a discussion!)


Dr. Robert Marion on Preimplantation Genetic Diagnosis

by Dr. Hsien-Hsien Lei
Posted August 20, 2009 in DNA Testing, Personalities with DNA

genetic rounds robert marionHere’s part 2 of my interview with Dr. Robert Marion, whose new book, Genetic Rounds, will be published in October. (See Part 1 for Dr. Marion’s thought on medical writing.)

One of the most touching aspects of Genetic Rounds was your concern for the families of patients affected by genetic disorders. Some would-be parents turn to preimplantation genetic diagnosis (PGD) so as to avoid passing down certain genetic mutations to their offspring. What are your feelings about PGD?

Dr. Marion: My feelings are mixed.  PGD is an amazing tool, an opportunity that allows families like the Kennedys in "Genetic Rounds" who, because of the birth of a previous child with a devastating genetic disorder (in their case, Spinal Muscular Atrophy) have decided not to have more children, to safely reproduce and raise a family.  As such, it’s a technique that allows babies who would not have been conceived to be born.  So, from that perspective, it is an incredible breakthrough.

The problem I see, however, is that I don’t think we’re certain of what effects PGD and in vitro fertilization in general  might be having on the pre-embryo and embryo.  Recent work showing an increase in conditions in which epigenetic disturbances may play a role, such as Beckwith Wiedemann syndrome, points to our need for additional information about how extra-corporal fertilization (a technique that’s necessary for PGD) affects gene silencing and gene expression.  Until these studies have been completed, we have to continue to be cautious.

However, I think the benefits of PGD clearly outweighs the risks. 


I recently received an email from a reader who’d undergone preimplantation genetic diagnosis prior to conceiving their children by IVF. Unfortunately, the genetic mutation they were concerned with was not picked up during the screening. With permission, here’s the email I received:

My wife and I underwent IVF and PGD testing to try and avoid passing on a genetic condition which she carries.  Her mutation had been previously identified by a certified and highly respected laboratory.  Three embryos were implanted and we were elated at the birth of our fraternal twin sons.  Almost immediately, my wife recognized the signs of her condition in one of our sons.  A blood sample was drawn from him and from my wife.  These were sent to another highly respected lab that confirmed 1) the initial laboratory successfully and properly identified my wife’s mutation and 2) our son has the condition.

The laboratory that performed our PGD refuses to respond to our inquires.  We just want to know and understand what happened — and that someone gives a damn.

Prior to undergoing the procedure, we thoroughly weighed and examined the moral and practical issues surrounding IVF & PGD.  I researched the topic as much as I possibly could and kept running across assurances such as "error rates approaching zero."  Heck, that’s better than what you get for any medical procedure! 

I can’t begin to explain to you how alone we felt.  It would be helpful to know that someone else has gone through this before… (emphasis added)

What are your thoughts on preimplantation genetic diagnosis? Do you have some kind words to share with this reader? For more information, see my previous post – Genetic Testing to Prevent Wrongful Life.



Yay or Nay for Genetic Testing?

by Dr. Hsien-Hsien Lei
Posted February 28, 2009 in DNA Testing

Today, CNN featured Dr. Robert Superko at St. Joseph’s Hospital in Atlanta, Georgia who is recommending genetic testing to patients at risk for cardiovascular disease.

Dr. Superko:

If you have heart disease and you have one of these heart disease genes, then the likelihood that is contributing to your problem is very high. If [the testing] gives you a therapeutic direction, a diet or drug to take, then it becomes valuable.

But he is not making a rare endorsement of direct-to-consumer testing:

It is easy to get confused about test results, especially those received through the mail. You may not understand what they mean and you can get unduly concerned.

Basically, it’s yay for genetic testing if you go through your doctor and nay for genetic testing if  you don’t.

Although, his patient, Donna Mitchell, might not agree:

I think you need to take advantage of everything you can to prevent problems. [Genetic testing] was a no-brainer for me.

(1 comment)


American Clinical Laboratory Association Tips for Consumers of Genetic Tests

by Dr. Hsien-Hsien Lei
Posted February 25, 2009 in DNA Testing

Lab Results for Life

Thinking about purchasing a genetic test? The American Clinical Laboratory Association (ACLA) recommends that consumers ask the following six questions:

1. Is the test done in a medical lab certified under the Clinical Laboratory Improvement Amendments (CLIA)?

2. Is a genetic counselor, physician or other knowledgeable health professional available to assist you in selecting tests and interpreting results?

3. Do the claims seem hard to believe?

4. Are other products, such as nutritional supplements, being sold along with the test?

5. Are you willing to be “an informed” consumer — that is, take the time to understand what genetic testing tells you?

6. Does the provider of the service offer adequate assurances that your genetic information will be kept private and secure?

The ACLA’s educational campaign “Results for Life” also has an informative storyboard about genetic tests (pdf) and how personalized medicine can help with each stage of diagnosis and treatment to predict, screen, diagnose, select treatment, and manage the disease.

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Navigenics Introduces Physician Portal and Annual Insight Service

by Dr. Hsien-Hsien Lei
Posted January 29, 2009 in DNA Products, DNA Testing

Consumers of genetic testing now have two new services to consider from Navigenics.

From the press release:

Navigenics’ Physician Portal

…Navigenics has developed the ability for physicians, with the approval of their patients, to receive and easily review patient genetic results online, with easy access to condition information, action steps, and original scientific research. Access to the physician portal is free to physicians who register their practices.

Annual Insight Service

Navigenics’ Annual Insight service retails for $499 and analyzes an individual’s genetic predisposition for ten common health conditions (nine each for men and women), including breast cancer, prostate cancer, colon cancer and heart disease.

Annual Insight also includes one hour of genetic counseling and if the consumer chooses to upgrade, the cost can be applied to the more comprehensive Health Compass service that includes a genome-wide scan, 24/7 genetic counseling, and ongoing updates for $2500.

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Parenting Children Using Genetic Tests

by Dr. Hsien-Hsien Lei
Posted January 11, 2009 in DNA Testing

troll dolls Trolls have been around these here parts. They’re upset because I wrote disparaging remarks about a particular company marketing DNA tests for detecting a child’s “innate talent.” But contrary to their accusations that I deny the genetic basis of behavior, predisposition, and temperament, I actually believe that many, if not almost all, human traits are influenced by genetic make-up.

My problem with genetic testing companies that target parents seeking to hothouse their children is that the biological mechanism of the few behavioral genes that have been identified are poorly understood. In addition, we have limited data on how these genes interact with other genes and with environmental exposures. Parents who think they will raise the next Bill Gates or Mozart by purchasing a test that focuses on a limited panel of genotypes are sadly deluded.

Last year I shared a Steven Pinker quote from Curious Minds: How a Child Becomes a Scientist that I think about all the time when parenting my own children:

With constitutional factors (genes and chance) being important but invisible, people tend to blur cause and effect in thinking back on supposedly formative childhood vignettes. …Rather than childhood experiences causing us to be who we are, who we are causes our childhood experiences.

This Sunday’s New York Times features My Genome, My Self – Steven Pinker Gets to the Bottom of his own Genetic Code in which Dr. Pinker points out that no matter how parents contrive to create the perfect environment for their children, when the children become adults, they will most likely gravitate towards experiences that suit their innate genetic tendencies. Would this be an argument for or against genetic testing in childhood?

A common finding is that the effects of being brought up in a given family are sometimes detectable in childhood, but that they tend to peter out by the time the child has grown up. That is, the reach of the genes appears to get stronger as we age, not weaker. Perhaps our genes affect our environments, which in turn affect ourselves. Young children are at the mercy of parents and have to adapt to a world that is not of their choosing. As they get older, however, they can gravitate to the microenvironments that best suit their natures.

Of course every parents has the right, and the power, to subject their children to genetic testing. In some cases, these tests may predict future debilitating diseases. And with these results, parents can help children live healthier lives with preventive lifestyle changes. Such is the power of genetic testing.

When it comes to genetic testing for academic, musical, or athletic talent, however, the results are far more ambiguous. Not only will the child be directly impacted by the results, the rest of the family will be impacted as well. Say parents scrimped and saved to get their child tested so they can make sure she becomes a success in life and help guarantee the family’s financial security. If the cost of the test plus other enrichment courses suggested by the test results impinge on the family’s overall well-being and lifestyle, it’s possible the investment may not be worth it. Or what if it turns out the child has a very average genetic profile? Would the parents be less likely to devote any time or effort into raising her?

Regardless, a child who supposedly has genes for high IQ may very well also have the trollism gene that relegates him to being a low-EQ jerk. Hardly a marker of future success. And as Peggy pointed out, genetic testing companies that target parents most likely will not include negative genes in any report. Nobody wants to be the bearer of bad news. Unless you’re a troll, that is.



Testing Children for Sporting Ability Genes

by Dr. Hsien-Hsien Lei
Posted January 8, 2009 in DNA Testing

track and field Word of warning if you’re thinking about “encouraging” your child to take up a sport based on his/her genetic test results.

In February 2008, a 15-year-old Singaporean boy committed suicide by jumping from his family’s 11th floor apartment. He had become a track and field star at his secondary school and was being pressured to continue the extra-curricular activity even though he wanted to pursue drama instead.

Parents walk a tightrope every day. We either feel that we’re too soft on our children or that we pressure them too much. Push them too little and they may fail to achieve their full potential. Push them too much and they rebel and go the opposite way, sometimes ending in tragedy.

With genetic test results in hand, parents may feel tempted to wave it in the child’s face and say, “But you can’t give up! Your destiny is here. You have two copies of the ACTN3 gene. You were born to be a track and field star.”

But sometimes, what’s in your genes isn’t in your heart. I’d rather my children followed their heart.



Ambiguous Results from Genetic Testing

by Dr. Hsien-Hsien Lei
Posted January 6, 2009 in DNA Testing

Tests = Questions + Answers

The above might apply in school but it doesn’t necessarily compute when it comes to genetic testing.

Last week, NPR aired a story on the Gilmore family. Dan Gilmore inherited a BRCA mutation from his mother who died of breast and ovarian cancer. On the other hand, his wife, Susan who had no signs of having cancer, was told that she most likely did NOT inherit a BRCA mutation despite a spotty family history. Whether or not she chose to be tested was up to her and was not as relevant as it would be for their three daughters.

fear uncertainty doubt Unfortunately, Susan’s genetic test results came back just as spotty. It turns out that she carries a variant mutation of “undetermined significance” which may or may not increase her risk of breast and/or ovarian cancer.

Susan is among the 10% of BRCA genetic test takers who get results of undetermined significance. Beth Peshkin, the Gilmores’ genetic counselor at the Lombardi Comprehensive Cancer Center at Georgetown University, says that as genetic testing becomes more common among asymptomatic people with no family history of disease, such uninformative results will become even more common. Given the type of people who currently take genetic tests for BRCA, around 1 in 2 people will receive ambiguous results.

Genetics Home Reference has more information on negative results that are “uninformative, indeterminate, inconclusive, or ambiguous”:

Uninformative test results sometimes occur because everyone has common, natural variations in their DNA, called polymorphisms, that do not affect health. If a genetic test finds a change in DNA that has not been associated with a disorder in other people, it can be difficult to tell whether it is a natural polymorphism or a disease-causing mutation. An uninformative result cannot confirm or rule out a specific diagnosis, and it cannot indicate whether a person has an increased risk of developing a disorder. In some cases, testing other affected and unaffected family members can help clarify this type of result.

While ambiguous results from the BRCA genetic test indicate uncertainty regarding the interpretation of results, inaccurate tests cause another type of ambiguity. For example, Baylor College of Medicine offers prenatal DNA testing that is more sensitive than those usually available. This genetic test can detect more than 200 genetic abnormalities in the fetus but critics question the accuracy of such a test and the consequences of false positive results. Dr. Arthur Beaudet says that ambiguous results occur in only 1 our of 100 pregnancies.

Amateur genetic genealogists may also find themselves in a quandary when results from different providers don’t match up. One Genealogy-DNA listserv participant purchased tests from three different companies. Two companies’ results matched up but the third did not. After a year of wrangling with the company, the lab manager finally admitted that a technician made a “stupid mistake.”

With respect to direct-to-consumer (DTC) genetic testing and ambiguous results, Heidi C Howard and Pascal Borry wrote in Future Medicine (PDF) that people who seek genetic testing even when there is no medical or clinical necessity “challenge the organization of public healthcare systems” because they will most likely receive “dubious and ambiguous results.” The authors suggest that these individuals would be better served with genetic counseling rather than testing itself.

Would you prefer having no results at all to ambiguous results? Or would you take the chance on getting informative results that may be bad news?

Artwork from flickr by Paul Downey

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