Advances in genetics and biotechnology are impacting society in provocative ways. The Genetizen is written by a select group of scientists, bioethicists, and healthcare professionals who provide you with expert analysis and commentary on many important issues.
Disclaimer: Opinions expressed in blog postings may or may not reflect the opinions of Geneforum. In addition, the content provided here is purely informational and not a substitute for advice from your personal physician.
Pharmacogenetics is the study of inherited differences in response to pharmaceutical drugs. One of the interesting issues lately has been the "discovery" that people of African-American heritage seem to react differently to drugs intended to reduce high blood pressure. Since the problem is more common among these people than those of other ethnic heritages, there seems to be some benefit to designing "ethnic" blood pressure medication.
What's funny to me is that, since the discovery of this effect, I haven't seen any drugs approved and advertised specifically for African-Americans. Perhaps this is the kind of result James Randerson was thinking of in the article I discussed yesterday, Risks of Online Genetic Testing.
The Geneforum poll on DNA tests has been running for quite a while. Currently, we have votes from 300 people. Of these, 44% have purchased or would purchase a DNA test. A similar percentage (44%) selected one of the "negative" options. As we might expect, few people added a comment.
Whatever your answer was, you may be interested in the following article, posted today on the Hindu News Update Service. The article actually came from London's Guardian News Service. Naturally, I latched on to it, since I am quite leary of genetic testing available online. Here's some of what the author James Randerson said.
The genetic testing services available at present can't give you the power to make effective and ethical decisions about how such tests might impact your life- though they might aspire to, or insist they can.
As I described earlier in a blog entry, the reliability of four companies was tested by a US Government Accountability Office investigation released in July (http://tinyurl.com/gzxur). Fourteen "different" samples--which actually came from only two subjects--were sent to these companies and the results compared. TheGAO's damning report shows that the companies - which charged between $89 and $395 for the tests - provided inconsistent results and offered vague and misleading advice to their "clients".
- Suracell from Montclair, New Jersey
- Sciona Inc of Boulder, Colorado
- Genaissance Pharmaceuticals of Newton, Massachusetts
- Genox and Genelex Corp of Seattle, Washington
Randerson's report goes on to describe pharmacogenetics--a field which is predicted to tailor treatment to a person's genetic makeup. I'll write more about that in the next entry.
To see all of Sanderson's article, go to http://www.hindu.com/thehindu/holnus/008200609070321.htm
Marie Godfrey, PhD
There's a series of comments at http://www.worldmagblog.com/blog/archives/026312.html that relate to a WorldView blog titled, Playing God in the DNA Age that you might find interesting. Susan Olasky writes as follows:
PGD is the method by which doctors test an embryo to see if it carries a gene for hereditary diseases like breast cancer and colon cancer, "that may or may not develop later in life, and are often treatable if they do." According to the New York Times, "already, it is possible to test embryos for an inherited form of deafness or a mild skin condition, or for a predisposition to arthritis or obesity. Some clinics test for gender. As scientists learn more about the genetic basis for inherited traits, and as people learn more about their genetic makeup, the embryo screening menu and its array of ethical dilemmas are only expected to grow. 'From a technology perspective we can test anything,' said Mark Hughes, director of the Genesis Genetics Institute in Detroit, who is performing P.G.D. this month for two couples who want to avoid passing on a susceptibility to breast cancer. 'The issue becomes what is considered serious enough to warrant such testing and who decides that.'"
Share your opinion with others by commenting here at the Genetizen forum.
Marie Godfrey, PhD
A recent online poll conducted by the Wall Street Journal Online and Harris Interactive Healthcare demonstrates that the U.S. public is generally supportive of genetic technologies.
[via Yahoo News]Â
"While only five percent of all adults have ever had a genetic test to study their DNA, the vast majority of U.S. adults (93%) feel that genetic science is a good thing, and few (only 1%) feel it is a bad thing. Furthermore, most adults are supportive of using genetic information for purposes such as to identify criminals (93%) and to treat disease (87%)."
The overwhelmingly positive response is a nice surprise to me.Â It renews my faith that people can see past the sensationalism often attached to genetics to the usefulness of this science for criminal justice, medicine, and predictive screening.
The poll also gauged public opinion about discrimination in employment, life insurance and health insurance.Â A strong majority (80%) agreed that genetic information should not be used by companies to affect eligibility for jobs or insurance coverage.
To summarize, the public supports the use of genetics in ways that will benefit and disagrees with the use of genetics to discriminate.Â
Makes sense to me.Â
Nicole Teed, MS, CGCÂ
In the UK, it will be illegal starting Sept 1 to take a sample of someone's DNA and have it analysed without obtaining their consent. According the New Scientist, in an article discussing the new law:
The legislation allows for some exceptions. For example, if a couple have a child and then separate, and the man has parental rights, he is entitled to have the child's DNA analysed without getting consent from either the child or mother. He could submit the DNA along with his own for paternity testing.
The new law, part of the Human Tissue Act 2004, applies to employers who want to check up on their employees, insurance companies hoping to avoid insuring expensive enrollees, and publicity hunters who follow celebrities around hoping to get a DNA sample.
Helena Kennedy, chair of the Human Genetics Commission (HGC), which advises the UK government, stated:
Until now there was nothing to stop an unscrupulous journalist from secretly taking an everyday object used by a public figure - for example, a coffee mug - get a DNA sample from it, have it analysed and then publish their genetic information. DNA sequencing has impact not only on one person but on their whole family's privacy too.
To the best of my knowledge, there's no similar law in the US. This sounds like a good idea for American public policy, especially with the large number of ways available to have someone's DNA analyzed without them knowing. If you haven't read it yet you might be interested in Vern's story, a part of the new Consumer's Guide to Genetic Testing now being beta tested on this website. Check it out by clicking on guide in the text of the home page.
Marie Godfrey, PhD
Today's online edition of the TimesDispatch from Richmond, Virginia sums up the benefits and drawbacks of medical family histories in a very readable way. Here's some of what the author Betty Booker has to say:
If Daddy died of a heart attack and Mommy had a stroke, you ought to keep yourself fit and lean. . . But, you knew that already, right? If Grandma had a stroke and Grandpop died at the office in a gray flannel suit, then you have more reason to get serious. And if your great-grandmother had a stroke cooking at the wood stove and your great-grandfather dropped dead plowing the north 40, you really do have a genetic inheritance demanding attention.
Here are some of the author's reasons for compiling histories and for genetic testing:
If you can piece together your health history, you can track disease and health patterns that could make a huge difference in your life and those of future generations. Knowing what diseases your kin had, and their causes of death, can help your doctor understand your own health problems--and better yet, teach you how to prevent them.
Preventing--or delaying--the onset of serious health problems by what you do to improve your health may prolong independence. And taking responsibility for your health based on your family history can save you a lot of pain, disability, surgeries, medicines and high medical bills.
Elders with serious health problems sometimes will get genetic testing as part of their legacy.
Some seniors elect to store DNA material to be used when more advanced tests are developed in order to help their children and grandchildren. [This is what I recently did with my husband's DNA.]
The "most common, costly and preventable" chronic health problems are heart disease; stroke; diabetes; and colon, breast, and ovarian cancer, according to
the U.S. Surgeon General. Knowing whether any of our ancestors had these problems, and making full use of the scientific information available about how to avoid these diseases or detect them early could significantly influence or own health future.
So, what are the potential problems?
Key people in our families may have already died without leaving details of their medical history. Collecting information isn't easy if your older relatives have memory problems.
The information that we collect generally is incomplete and it may not always be accurate.
The information is highly personal--"and not all of it is yours. If your history includes an aunt's breast cancer and a brother's depression, for instance, their private information should be protected."
There's always a chance your information can get into the wrong hands--especially if you complete personal family history forms online. However, online forms that are connected to databases of information can give you predictions about how your family's health history may affect your own future--if you understand what the "predictions" mean.
The author concludes: "Family health histories are part of a larger trend of data-rich medicine. . . Instead of working on a lot of hunches about how a patient should be treated--which is still pretty much how medicine works today, doctors in the future will have huge population databases to guide their decision-making about individuals based on evidence of their genes and other factors."
The steps are straightforward--if you can get the medical information you need. To start, prepare for your next family gathering--large or small--by checking out one or more of the following websites:
Enjoy! Creating your family's medical history is not only worthwhile, it's fun.
Marie Godfrey, PhD
The recent announcements that a commercial company has been able to create stem cell lines without destroying embryos has hit most of the news programs and other outlets--with the expected feedback.
The technique involves the removal of a single cell from an 8-cell embryo (outside the human body) and culturing this cell to produce stem cells. The arguments against "destroying embryos" presumably do not apply because the embryo is not harmed in the process. You may remember that harvesting cells from a more-developed blastocyst--after the embryo has developed into a hollow ball with an inner cell mass--does destroy the embryo.
So, why 8 cells?
- The previous cell division--which doubles the number of cells in the embryo--was made by a 4-cell embryo. One cell of an embryo at this stage could become a fetus--with perhaps 3 other babies created from the other 3 cells, giving the parents quadruplets.
- Cell division is so rapid in the newly fertilized egg that "catching" an embryo at the 8-cell stage requires careful attention. Presumably, some of the embryos could be any number of cells prior to formation of the blastula. This is why the news reports tend to say "8-to-10-cell stage". Also, the cells do not necessarily divide simultaneously.
- There are many reports that cells at early stages of division may not be genetically identical. Rapid cell divisions in the embryo may sometimes produce cells with very slightly different DNA content.
- In pre-implantation genetic diagnosis, cells have been successfully removed from embryos of 8 cells or more without harming the embryo. This one is a bit tricky to prove, though, since more than one embryo so examined is usually introduced into the uterus for development into a fetus. If only one of 2-4 embryos develop into a fetus, there's no way of knowing why the others did not so develop.
- Smoke and mirrors--there appears to be less public concern about an embryo with one cell removed than there is about a blastula with its germ cells removed. Good publicity for a commercial company and eventually great profits from newly-created cell lines.
Here are some considerations you might not have thought of--whatever your opinion about embryonic stem cells and their creation:
- What will happen to the rest of the embryo? If it will be discarded, or used for potentially creating additional stem cell lines, this technique is no different from any technique that destroys an embryo.
- Is the technique useful only for people planning in vitro fertilization and pre-implantation genetic diagnosis? If so, would two cells have to be removed--one for the genetic diagnosis and one for the stem stem line? Will removing two cells damage the embryo?
- Will there be a market for embryos created solely for generating stem cell lines?
- How will stem cell lines be created for diseases such as Alzheimers or other adult-onset conditions generally occurring when a person is no longer fertile?
- If the embryo is yours, do you get the rights to any money made from the stem cell line(s) developed from that embryo?
- If the method is so successful, how come only 2 cell lines could be created from 81 embryos?
Want to add some comments of your own? Please do.
Marie Godfrey, PhD
My father and my grandfathers were alcoholics. Luckily, I escaped that fate. I do, however, have an addiction and that is to food. I constantly struggle with the urge to eat and overeat.
That's why a news release from the National Institutes of Health interested me today.
Researchers at the Molecular Neurobiology Branch of the National Institute on Drug Abuse (NIDA), National Institutes of Health, have completed the most comprehensive scan of the human genome to date linked to the ongoing efforts to identify people most at risk for developing alcoholism. This study represents the first time the new genomic technology has been used to comprehensively identify genes linked to substance abuse. The study can be viewed online and will be published in the December 2006 issue of the American Journal of Medical Genetics Part B (Neuropsychiatric Genetics).
NIDA researchers found genetic variations clustered around 51 defined chromosomal regions that may play roles in alcohol addiction. The candidate genes are involved in many key activities, including cell-to-cell communication, control of protein synthesis, regulation of development, and cell-to-cell interactions. For example, one gene implicated in this study â€” the AIP1 gene â€” is a known disease-related gene expressed primarily in the brain, where it helps brain cells set up and maintain contacts with the appropriate neighboring cells. Many of the nominated genes have been previously identified in other addiction research, providing support to the idea that common genetic variants are involved in human vulnerability to substance abuse.
Genome is the total genetic information of a particular organism and genetic variation is used to describe differences in the sequence of DNA among individuals. Genetic variation plays a role in whether a person has a higher or lower risk for getting particular diseases.
So, there are potentially many different factors--some of them genetic--that may be involved in addiction to alcohol, drugs, food, and--some studies say--dangerous behavior.
Marie Godfrey, PhD
Genetic counselors are currently licensed in Utah. Outside of Utah, genetic counselors practice without a license. Most are well-qualified and ethical health care professionals. Many are board-certified by the American College of Genetic Counseling, but certification and licensure are two different things.
There has been a push in the genetic counseling community in recent years to support licensure in other states, and eventually nationwide. As the availability of genetic testing increases, so does the risk of an unqualified (or underqualified) person hanging out their shingle, calling themselves a genetic counselor, and endangering the well-being of those who choose to pay them a visit. Licensure ensures that healthcare professionals are qualified to perform their jobs and defines their scope of practice. It also gives the public a course of action should they want to file a complaint.
Counselors in a number of states are in the process of drafting legislation to require the licensure of genetic counselors. Some state groups have gotten as far as a bill on the floor only to uncover unexpected opposition from other lobbying groups. Because these changes have to occur on a state-by-state basis, we are learning about the best approaches as well as the barriers as we go.
Doctors, nurses and other allied health professionals are licensed. Massage therapists are licensed. Hairstylists are licensed. Realtors are licensed. The list is long.
It makes sense to me that if the person cutting my hair needs a license, so should a genetic counselor. After all, hair grows back. The impact of genetic testing and diagnosis can change a person's life.
What do you think?
Nicole Teed, MS, CGC
The day before my husband died, I gave consent to have blood samples taken from him for storage and possible studies on the genetics of brain cancer. I did this primarily for our children and their children.
If, in the next 5 or 10 years a study is planned to identify some of the genetic connections for glioblastoma multiforme, I can have his DNA used in that study. I can also reclaim the DNA sample for my family's use if I wish. Meanwhile, the information in his DNA sample is protected from use except for the study for which I gave informed consent.
Although I could have purchased a genetic test available from one or more companies offering such testing, I know of no current information on the genetic components of brain cancer, except for sensitivity to Temodar, the current standard chemotherapy. There would have been no immediate benefit to my family and his DNA information would have been exposed to possible privacy invasion.
As I recover from the trauma of his death--45 days after the diagnosis of a brain tumor and 22 days after he slipped into a post-surgery coma--I will return to writing blog entries. Â
Marie Godfrey, PhDÂ
Several newspapers lately have reported on the General Accountability Office's testing of genetic tests sold online. According to the U.S. News and WorldReport, "these 'direct-to-consumer' genetic tests, which cost from less than $100 to over $1,000, have proliferated on the Internet in recent years, many promising to give consumers genetically based nutritional advice or advance warning of life-threatening illnesses."
Unfortunately, the GAO report concludes that the tests make predictions that are medically unproven and "so ambiguous that they do not provide meaningful information."
According to news reports, "the GAO investigators took two DNA samples via cheek swab, one from a 48-year-old GAO employee and one from the 9-month-old daughter of Gregory Kutz, the GAO's managing director of forensic audits and special investigation, and submitted the two samples under 14 phony names. The online firms reported back that the 14 fictitious customers were at risk for a wide-ranging list of serious diseases, including cancer, diabetes, and high blood pressure--despite the fact that only two people were tested."
The Senate Select Committee on Aging held a hearing on the GAO's findings last week. Genetic science holds great promise," said Republican Sen. Gordon Smith of Oregon, chairman of the committee, who requested the GAO investigation. "Clearly, consumers are being misled and exploited by this modern-day snake oil, and I am shocked to learn how little the federal government is doing to help consumers make informed decisions about the legitimacy of these tests."
The Federal Trade Commission is also urging consumers to be cautious about over-the-counter genetic tests, noting that companies may post your results online, which could raise privacy concerns. A new brochure offers tips and advice on these new at-home tests.
Many of your questions can be answered here, right on the Geneforum website. Check out the new Consumer's Guide to Genetic Testing.
Marie Godfrey, PhD
Statistics are just meaningless numbers until you are trying to determine how long a loved one may live or what your chances are of having a particular disease.
I hope readers will bear with me for lapses in posting blogs. My husband joined the group of 17,000 or so diagnosed each year with a brain tumor. He chose surgery and we are now anxiously waiting to see whether he will come out of the drug-induced coma and resume the shortened life expectancy he was given along with the diagnosis.
Numbers suddenly have a whole new meaning.
As conditions improve--we pray--I will gladly return to scanning the news and posting blogs. I have some interesting information from the Genetic Alliance conference and lots more to report.
Marie Godfrey, PhD
The numbers and statistics in the following blog entry are almost guaranteed to confuse you.
The article under discussion here, in the Journal of the American Medical Association, is titled: "Salpingo-oophorectomy and the Risk of Ovarian, Fallopian Tube, and Peritoneal Cancers in Women With a BRCA1 or BRCA2 Mutation." It appears in volume 296, pages 185-192. The original article is available only by subscription or from the authors. Information here comes from the abstract. Definitions are at the end of this entry if you need them.
The authors conclude:
Oophorectomy is associated with reduced risk of ovarian and fallopian tube cancer in high-risk women, although there is a substantial residual risk for peritoneal cancer in BRCA1 and BRCA2 mutation carriers following prophylactic salpingo-oophorectomy.
They also state, in the results:
The overall (adjusted) reduction in cancer risk associated with bilateral oophorectomy is 80% (multivariate hazard ratio = 0.20; 95% confidence interval, 0.07-0.58; P = .003).
O.K., so, according to this article, if you have one of the BRCA mutations, and you have your ovaries and fallopian tubes removed, you can still get ovarian or fallopian tube cancer [???]. You are also still at risk for peritoneal cancer. The 80% reduction in cancer risk sounds pretty good, though. If I hadn't already had my ovaries removed (they didn't tell me whether they removed the fallopian tubes), I'd probably consider this surgery if I were found to have the BRCA1 or BRCA2 mutation.
But what do the study numbers tell us?
1. The study was retrospective--1828 patients with BRCA1 BRCA2 gene were identified from an international registry between 1992 and 2003. Because it is only 2006, it is possible that women identified for the study will develop cancer (or die) in the future--only these occurrences in the past were considered in the analysis of the results. We do not know what will happen to the current "survivors". Also, the abstract doesn't identify how many women were "lost to follow-up" (that is, have data only for part of the study period).
[By the way, those of you worried about genetic privacy, do you wonder what this international registry is and where it gets its data? I certainly do.]
2. The data for the women were first split into those who had no oophorectomy 783/1828 (43%) and those who did: 555 (30%) prior to the study period and 490 (27%) during the study period. O.K. 43 + 30 + 37 = 100%; so far, so good.
3. By the end of the study period, 32 of the 783 women who had not undergone surgery developed cancers [the abstract doesn't say what type, but ovarian, fallopian tube, or peritoneal is implied]. This is reported, not as 32/783 (4.1%), but as 1015/100 000 per year.
4. Of the women who had undergone surgery, eleven cancer cases were identified at the time of prophylactic oophorectomy and 7 were diagnosed following prophylactic oophorectomy. This is reported in the abstract as 217/100 000 per year. The fraction 18/1045 (11 + 7 = 18 and 555 + 490 = 1045) is 1.7%.
5. If you compared 4.1% with 1.7% (over the short course of the study), you might say that among women with a BRCA1 or BRCA2 mutation, those who had no surgery (oophorectomy) were 2.4 times as likely to develop cancer compared with women who had prophylactic (pre-emptive) surgery (4.1 divided by 1.7). [Note that the wording is "as likely", not "more likely".]
6. If you compared the per-year numbers 1015 vs. 217, you could say 5 times as likely (1015 divided by 217).
7. If you did a "survival analysis" [as the authors did], you would find "The overall (adjusted) reduction in cancer risk associated with bilateral oophorectomy is 80% (multivariate hazard ratio = 0.20; 95% confidence interval, 0.07-0.58; P = .003)."
So, which is the "real" number?
Just one more set of numbers: Only about 5-8% of women have a mutation in the BRCA1 or BRCA2 genes. Many sources report that mutations of the BRCA1 and BRCA2 genes give women a higher risk of developing ovarian cancer (15 percent to 54 percent), than women without the mutation.
So . . . do you have a test for BRCA1 and BRCA2? . If you find out you have one or more mutations in these genes, do you have the removal surgery? If so, have you now eliminated your chances of having ovarian, fallopian tube, or peritoneal cancer? The answer is, No.
The purpose of spouting all these numbers is to help you understand that news articles select the numbers that seem simplest to them; the deeper you dig, the more likely you are to wonder about the validity and practicality of those numbers.
Marie Godfrey, PhD
Definitions: Salpingo-oophorectomy--removal of ovaries and fallopian tubes. Peritoneal-- the peritoneum is a membrane that forms a sort of envelope around your abdominal organs and also lines your abdominal cavity
A couple of days ago, I happened to catch a set of reversed numbers in a blog posting at Genetics and Health. Hsein, the author, had posted the following as part of a discussion of the ATM gene in breast cancer:
A recent study has found that women who carry the ATM mutations. . . are:
- Twice as likely to develop breast cancer.
- At higher risk of developing breast cancer by age 70 (1 in 12) than those who donâ€™t (1 in 6).
I wrote to Hsein and suggested that 1 in 6 was a higher risk than 1 in 12, and that there might be an error. Hsein was quick to change the 1 in 12 to 1 in 6 and the 1 in 6 to 1 in 12. She the numbers when she read my note about the error, and was even sharp enough to mark the change in her post by putting strikehroughs on the incorrect numbers (which I can't seem to reproduce here):
Then, today, I was confused when I read an article about a new drug treatment for brain tumor. The connection to Ivanhoe.com came from a news alert I receive and said:
On the site this week we have a couple of reports from the H. Lee Moffitt Cancer Center, including . . . a targeted therapy for treating specific brain tumors that occur in about one in every four patients.
The article itself had the following numerical statements:
SDX only works in those who lack the MTAP gene -- that's about one in every four patients.
About one in every four patients with brain tumors lack the gene that lets them qualify for this therapy.
The beginning of the article implies that 1/4 of patients with brain tumors have this specific tumor. The statement about SDX seems to equate lacking the MTAP gene with having this specific type of brain tumor. And then, in the last example above, a reader could interpret the sentence as meaning "three of every four patients with brain tumors have the gene that lets them qualify for this therapy." If you're a brain tumor patient, or a family member, 3/4 gives you a lot more hope than 1/4.
When numbers are reported, read the text carefully and be sure you understand the "real" intended numbers. There are enough problems with inaccurate numbers; we don't need to trip over numerical confusions within media reports.
Marie Godfrey, PhD
Overlooked in the hype about Bush's veto of "stem cell enhancement bill", which started out as H.B. 810, is the third of the stem cell bill package: S.2754. This bill is intended to direct NIH to fund research to derive human pluripotent stem cell lines using techniques that do not knowingly harm embryos. S.2754 is also known as the Santorum bill.
The Senate passed this bill unanimously (by counting yeas and nays) and turned the bill over to the House for its first consideration. On 18 July, the bill failed to pass, not being agreed to in the House. A motion was made to suspend the rules and pass the bill failed by yeas and nays 273 to 154 (a 2/3 majority is required).
I cannot tell whether the Senate-passed bill is still alive.
One possible reason for problems in the House maybe the bill (HR 5526 IH) the House introduced 6 June with a similar purpose, although--as far as I can tell, the bills are identical.
Marie Godfrey, PhD