Wednesday, June 3. 2009
As a follow up to Does the Government Have Your Child's DNA, I found this chart put together by Citizen's Council on Health Care. It lists State by State government newborn blood & baby DNA retention practices. Going back to 2001, it lists whether or not your state stores your child's blood from a newborn screening card, and for how long. And remember, the blood and DNA on those cards are considered the property of the state.
If you have children 8 years or younger, I would recommend finding out if your child's blood is being stored by your state. Two of my children will have their newborn screening cards stored until they are adults.
If the information on this chart bothers you, I suggest contacting your state representatives and let them know. As parents we should be fully informed about what happens to our children's DNA once it leaves their bodies. Parents need to be given the option of having their child's sample be destroyed after the testing is done. Any storage or use of their child's DNA for research should be an "opt in" situation where informed consent is given by the parents for any use outside the scope of the initial genetic testing.
Wednesday, April 1. 2009
Daniel MacArthur at Genetic Future has a hilarious, yet important, post on the genetic testing company 23andMe's marketing to pregnant women. 23andMe has recruited "mommy bloggers" to experience a genome scan as a way to "explore the genetic legacy your child will inherit from you and your partner." Daniel writes:
I never before thought of the genome revolution as a feminist movement, but I see the appeal. Frankly, it scares me a little. I love my gender, but we are not always known for our clear, rational thinking in situations that are fraught with emotion. I fear that a genome scan in a pregnant woman's hands is a ticking time bomb of genetic determinism. One that a general practitioner or obstetrician probably cannot diffuse. Steve Murphy, Gene Sherpa, points out:
I hope that 23andMe really want to give pregnant women information to help them raise healthier children. I am afraid it is simply a marketing ploy that preys on pregant women's fears. Time will tell.
Wednesday, March 18. 2009
Trisomy 13 is a genetic condition that often causes death either in utero or shortly after birth. It is a devastating diagnosis for parents and my heart and prayers go out to all families who have dealt with trisomy 13 or will have to in the future.
But, there is always hope. There are children that survive with trisomy 13. I found the Living with Trisomy 13 website yesterday and was encouraged and sickened all at the same time. Check out the photo album of angelic faces of children with trisomy 13; it is amazing. And the testimonies of parents who have loved and lost children with trisomy 13 are truly beautiful.
I was encouraged by the strength and love of these families and sickened by the stories of the so-called "medical professionals" that they had to encounter. On the Considering Abortion? page I found this letter to parents:
"Discouraged from researching the disorder for themselves"? "Given NO HOPE"? I cannot say I was shocked, but I was surely saddened. And then I got very angry reading the testimony of a women who did abort her trisomy 13 baby:
And again. Another woman is clearly devastated :
We went back to genetics counselor office and she explained what she thought it could be and told us what everyone has heard "incompatible with life". She told us, “he would live no longer than two days”. We had some difficult decisions to make.
It is apparent these women were failed by the people they needed the most. The doctors and genetic counselors that did not properly educate these parents and then pushed abortion as a solution are a disgrace to the medical profession. And I know these are not isolated cases. I am reminded of this quote from Lori B. Andrews, a reproductive rights lawyer:
"Ordered to abort"? I feel sick. Any doctor or genetic counselor that does not provide their patients with all the information to make an informed decision about a child with a genetic condition, not only fail their patients, but give all genetics a bad name.
I am even more thankful now for the The Prenatally and Postnatally Diagnosed Conditions Awareness Act that is meant to help get parents the information they need. The medical profession should not need legislation to make it do its job, but that is the state of our death-obsessed society.
Be Not Afraid is a great website to help parents who have gotten a difficult prenatal diagnosis.
Monday, March 16. 2009
I was sent this two part series on the Scripps Genomics Health Initiative by the author himself (Signed "Self-promotionally yours". Thats a good one. I'll have to remember that.) Randy Dotinga, along with 2,600 other people spit, a lot, into a tube and had their DNA tested for their risk for developing eighteen diseases. I will let you peruse his thoughts but I wanted to point out something that often gets overlooked when a person get their test results. In Part I, Randy muses:
Randy and his spit
Sorry Randy, I think your genes probably do know. Because it isn't just about what genes you have, it is about which genes are expressed and I would bet my first born that Ben & Jerry's addiction effects the expression of your DNA. So while currently, the tests you have gone under can only tell you what sequence of nucleotides you inherited, there is a whole other layer. Which I was happy to see pointed out in Part 2:
I wanted to commend Randy for taking part in this study. There are many risks to handing your DNA to a research study, but hopefully your DNA, (and your addiction to Ben & Jerry's), will help scientists and doctors better understand genetic testing and its consequences.
Friday, March 6. 2009
Cancer is a genetic disease. Not the kind of genetic disease that you are thinking. Cancer is caused by an accumulation of errors in DNA that take out a cell's natural growth control mechanism. The cell divides out of control and cancer is the result. Depending on which errors a tumor has, determines the genetic make-up of the cancer and the treatment that will yield the best result. Testing the genetics of a tumor and tailoring the treatment accordingly is a new approach to cancer treatment.
Massachusetts General Hospital has announced that they will do extensive genetic testing on nearly all tumors in new patients. From Boston.com:
John, Paul, George and Ringo. Now that is my kind of molecular diagnostics lab!
Thursday, February 26. 2009
Like all areas of genetic testing, it would be nice if the answer was a simple yes or no. Unfortunately, this early genetic test, that looks at small amounts of fetal DNA floating around in the mother's blood, has some good and some bad. Before we get to the ethical implications, let us look at the test itself.
Currently, the prenatal screening for Down Syndrome is not very reliable. It consists of checking the mother's blood for levels of certain factors that can predict if she is carrying a Down Syndrome child. This blood test is combined with ultrasound. If both indicate that the fetus may have Down Syndrome then an amniocentesis can be done. Amniocentesis can cause miscarriage and some doctors estimate that for every three Downs babies that are detected with amniocentesis or chorionic villus sampling (CVS), two healthy babies are lost to miscarriage.
That would certainly be an improvement over the current offerings. If claims are true, this test would mean more accurate diagnosis, which is always good, and would mean less CVS and amnios. Which in turn would mean less miscarriage. That is certainly good. And there is nothing inherently wrong with prenatal testing, as long as it is not done with abortion in mind.
Unfortunately, like all prenatal testing in a country where abortion-on-demand is the law of the land, I am positive this test will have devastating consequences. While the test will be more accurate, it will also make obtaining an abortion just that much easier because it would be performed in the first trimester. And the test for Downs will be just one of many more that will be coming.
Eugenics is back, and like in Edwin Black's book "The War on the Weak," the weak and voiceless "defectives" will be at the mercy of the medical establishment that thinks it is doing humanity (and the aborted fetus) a favor. In the early 20th century, well-meaning eugenics lead directly to the Nazi Holocaust. This time I fear the new eugenics will end in a GATTACA inspired nightmare where anyone with a genetic defect will have to defend their existence. Andrew J. Imparato of the American Association of People With Disabilities agrees:
People could start wondering? I think they already are. Somehow in our arrogance we have decided that the world would be a better place without people with Downs and other genetic abnormalities. I disagree and so does Dr. Brian Skotko:
Once again with the future tense. If there was a world with fewer Down syndrome people? It already is such a world. This test in our world of "reproductive freedom" will make it more so.
So is this early genetic test for Downs good or bad? I think the test itself is fine. It is the society that it is being offered to that has the problem.
Tuesday, February 24. 2009
There are more and more companies offering genetic tests directly to you without a visit to the doctor. There will be more. I expect that like drug ads on television, soon there will be ads selling you genetic tests while you are sitting on your couch, munching on chips and watching home improvement shows.
The American College of Medical Genetics (ACMG) has some recommendations for you if you decide to get a genetic test direct from a genetics company. I have discussed all of these in some aspect on this blog, but I will add some more commentary and some links for those of you that want to read more. From the Washington Post (recommendations of the ACMG in italics and bulleted):
In other words, genetic counseling is critical to understanding your results. Either the company should have one on staff that you can talk to, or you need to bring your result to a genetic counselor in your area. This is what can happen without proper counseling.
This means that just because a test shows you that you may have a particular gene variant that is associated with a disease, that does not mean that you will show symptoms of that disease. Environment and other genes play a significant role in the expression of a gene. More on this.
Often the clinical relevance of a gene is not well known. Just because a company offers a test does not mean they know what that test really means. There should be evidence that a particular gene is associated with a particular clinical outcome and this information should be readily available and well documented. More on what happens when a genetic mutation does not mean what geneticists think it means.
This one is very important. A reputable genetics lab will be accredited by a regulatory body like the College of American Pathologists and will be inspected at least every 2 years. There are labs that are not accredited or should not be. The nature of genetic testing lends itself to false positive and false negatives if the labs are not meticulous about their quality control. More on regulation of genetic testing labs.
Before you give any company a biological sample, you must know what will happen to that sample and the information it provides after the test you ordered is completed. Will they keep your sample? For how long? What is done with the genetic information? Will your DNA be shared with other genetics labs? Will the genetics company "own" your sample and the DNA therein once it is in their possession? Will further testing be done beyond the test you ordered? All question you must ask. More on what happens to your DNA once it leaves your body.
The above is very sound advice for those do-it-yourself-ers out there.
Tuesday, February 17. 2009
In case you are interested in a career in genetic counseling, (a profession that will become more and more in demand as the era of genetic testing continues) the Wall Street Journal has a great career profile: For Some Counselors, It's in the Genes
Thursday, February 12. 2009
I just could not pass this one by, because today, I need a laugh. From National Geographic:
Now that is some seriously old excrement!
Friday, January 23. 2009
Any reader of this blog knows that I am no fan of direct-to-consumer genetic testing. It is great that we can know all kinds of things about our genetics by just sending a few hundred bucks and a Q-tip to a genetics company. The problem lies in what those genetic sequences MEAN. Unfortunately, in many cases even medical professionals have no idea. Any genetic testing should be accompanied by credentialed genetic counseling, so bypassing your doctor's office in search of genetic answers may not always be wise. I have written before about the pitfalls of only having part of the genetic puzzle and how that effects patients.
Photo: Ye Rin Mok
Of course there are exceptions and this story of a father personally sifting through his daughter's genetic code looking for answers to her rare genetic disorder fascinates me. Beatrice Rienhoff's condition has been reviewed by some of the top experts in the country and no one could give her parents answers.
So her father took matters into his own hands. Hugh Rienhoff has had his daughter Beatrice's DNA extracted, he amplified it, sent it out for sequencing and is now looking at the sequence base by base looking for genetic abnormalities. Being that DNA sequencing is my area of expertise, I cannot even begin to relate what a monumental task this is. The wet lab work alone would have sent most packing. (I cannot believe he got his hands on the reagents.)
I want to encourage Hugh in his effort. I believe it to be a beautiful expression of a father's love for his daughter. So what makes this case different? Hugh Rienhoff is no ordinary Joe:
Currently genetics has no answer for Beatrice, so Dr. Rienhoff has gone looking for them himself. Kudos to him. He may never find them. But he clearly loves Beatrice in spite of her unknown "genetic defect":
Tuesday, January 6. 2009
Previously, I wrote about the morally acceptable aspects of genetic testing. There are many. Now I want to talk about the unethical uses of genetic testing.
Most of genetic testing is like money. That is, it is neither moral nor immoral. Money can be used for good or evil, but it in and of itself it is morally neutral. Genetic testing simply provides information. What is done with that information is where the ethical issues arise. Clearly, if the information used from genetic testing is used to discriminate against an otherwise healthy individual, then that would be immoral. There are endless scenarios of where the information provided by genetic testing goes very wrong. I do not want to delve into this area of ethics because it would be like writing about the endless ways money can be used for evil.
What I do want to discuss are the times when genetic testing is implicitly wrong. There are only two times when genetic testing is inherently evil: prenatal genetic testing with the intent to abort and preimplantation genetic diagnosis.
Most prenatal testing is done to learn more about the fetus and to help parents and doctors prepare for any complications or genetic disorders. It is true that many times the end result of the testing is abortion, but that is NOT the original intent of the testing. In this case the genetic testing is morally neutral, while the use of the information is morally wrong.
Prenatal genetic testing is immoral when the intent is to abort if an unfavorable result is returned. This would be the case if a couple wants a boy, and gets genetic testing with the intent of aborting if the fetus is a girl. Also, if a couple has an amniocentesis knowing that if their child has Down Syndrome, or any other genetic disorder they will abort. Rev. Tadeusz Pacholczyk, the Director of Education at the National Catholic Bioethics Center writes in his essay, "Prenatal Testing Brings Moral Dangers":
"If prenatal testing is done with the intention of having an abortion when a defect is discovered, such prenatal testing itself would constitute a gravely immoral kind of action. Even if no anomalies were found, but a mother and father carried out prenatal testing with the firm intention of aborting a defective child, they would be culpable for a seriously sinful decision, and, if they were Catholics, they would need to bring the matter to confession. The intention to commit a serious evil, even if not ultimately acted upon because of circumstances, constitutes grave sin."
Father Pacholczyk also confirms that in general prenatal testing can be a moral good:
"Prenatal testing is permissible, indeed desirable, when done with the intention of providing early medical intervention to the child. For example, the life-threatening disease known as Krabbe's leukodystrophy can be successfully treated by a bone marrow transplant shortly after birth. If a diagnosis of the disease is made by prenatal testing, the family can initiate the search for a matched bone marrow sample even before the child is born. That way, valuable time can be saved, and the early intervention improves the likelihood of a good outcome. Certain other diseases like spina bifida can be treated by doing microsurgery on the baby while still inside the womb. Prenatal testing which aims to provide diagnostic information to assist in the treatment of an in utero patient represents a morally praiseworthy use of this powerful technology.
The second time when genetic testing is inherently immoral is in the case of preimplantation genetic diagnosis or PGD. PGD is used to screen embryos created in a laboratory with in vitro fertilization for certain genetic traits. In PGD, a single cell is taken from an embryo and tested for as many as 6,000 different genetic variations. The intent of PGD is to find the most genetically desirable embryos to implant and embryos that do not make the cut are either discarded, donated to research or put in the deep freeze.
There are multiple ways in which PGD is immoral. First, the embryos that are tested are created by in vitro fertilization or IVF. In IVF, eggs are extracted from the mother and united with sperm from the father in a petri dish completely removing the unitive aspect of sex from reproduction. The Catholic Church has many reasons why IVF is immoral, most notably that every human being has a right to be created out of love for love in their mother's womb, not in a laboratory by a third party. It is against the dignity of every human being to be mass produced in a petri dish. Unfortunately, IVF treats human embryos more like man-made commodities rather than young lives deserving of the dignity given to the rest of humanity.
Nowhere is this more evident than in the practice of PGD where the newly created embryos are subjected to genetic testing that is intended to find out which of them make the genetic cut. Like the prenatal testing with the intent to abort discussed previously, PGD is genetic testing with the intent of discarding the human beings that "fail" the test. This fact alone makes PGD immoral.
Often PGD is used to find an embryo that is a genetic match for an older sibling who has an fatal disease and needs a transplant. In this case, PGD is used to screen for certain genetic traits instead of against genetic defects. The chosen embryos are implanted and brought to term with the express purpose of becoming a tissue donor for their older sibling. Here PGD is used to create human beings that are desired only for their biological material. A BBC News headline once called these children "spare parts babies."
In the recent Instruction Dignitas Personae on Certain Bioethical Questions, the Congregation for the Doctrine of the Faith wrote the following on PGD:
Unlike other forms of prenatal diagnosis, in which the diagnostic phase is clearly separated from any possible later elimination and which provide therefore a period in which a couple would be free to accept a child with medical problems, in this case, the diagnosis before implantation is immediately followed by the elimination of an embryo suspected of having genetic or chromosomal defects, or not having the sex desired, or having other qualities that are not wanted. Preimplantation diagnosis – connected as it is with artificial fertilization, which is itself always intrinsically illicit – is directed toward the qualitative selection and consequent destruction of embryos, which constitutes an act of abortion. Preimplantation diagnosis is therefore the expression of a eugenic mentality that “accepts selective abortion in order to prevent the birth of children affected by various types of anomalies. Such an attitude is shameful and utterly reprehensible, since it presumes to measure the value of a human life only within the parameters of ‘normality’ and physical well-being, thus opening the way to legitimizing infanticide and euthanasia as well”.
Finally, PGD is immoral simply because it puts the life of the embryo being tested at grave risk. In PGD, a needle is inserted into the tiny embryo and a single cell is extracted for testing. Needless to say, some embryos do not survive the biopsy. And there is the chance that those children that do survive the process and are implanted may have life-long health problems. PGD is clearly about what the parents want, not about the health of the resulting child.
Genetic testing is meant to provide information to help doctors, nurses and family provide better medical care. It should be a step toward making humanity healthier. Genetic testing goes very wrong when it is used with the intent of discarding the human beings that are not genetically desirable. Unfortunately, eugenic abortion and PGD are often described as eliminating disease. We must remember that PGD and eugenic abortion do not eliminate disease. They only eliminate the human beings that have the disease. This is what makes them inherently immoral.
Wednesday, December 3. 2008
I have found that many Catholics are confused about genetic testing and the ethical issues that surround it. So I have decided to write a two part series on the ethics of genetic testing.
Part 1: Genetic testing is not all bad.
A colleague’s battle with cancer is a good example of the use of genetic testing to prevent disease. We now know that mutations in the BCRA1 or BCRA2 gene put a woman at high risk of developing breast or ovarian cancer. My colleague’s mother, aunts, and cousin had breast or ovarian cancer. She, herself, was an ovarian cancer survivor. When the test for mutations in the BCRA1 gene became available, she found that she did have the mutation. Her sister was also tested, had the mutation, but had yet to develop cancer. Knowing she was at high risk, the sister underwent preventive surgery and now regularly gets screened for tumors. Hopefully, she will never develop cancer, but, if she does, it will be caught early, increasing her chances for survival.Doctors often use genetic testing to help treat their patients. A good example is the test for a mutation in the Factor V Leiden gene. Factor V Leiden is the most common hereditary blood coagulation disorder in the United States. Patients with a mutation in this gene are at greater risk of developing potentially deadly blood clots. If a doctor knows that a patient has an increased risk of developing a clot, they can prescribe medication or monitor the patient closely after surgery.
Genetic testing also provides information on Hereditary Hemochromatosis (HHC), the most common form of iron overload disease. HHC is an inherited disorder that causes the body to absorb and store too much iron. If the disease is not detected early and treated, iron will accumulate in body tissues and may eventually lead to serious problems. Mutations in the HFE gene are the thought to be the cause of HHC. A genetic test can identify patients who are at risk for developing HHC before they begin to have symptoms. In fact, there are countless such conditions and diseases, linked to genetic factors, that will be positively impacted by genetic testing, including diabetes and Alzheimer’s disease.Genetic testing has also created an exciting new field called pharmacogenetics. Pharmacogenetics is the study of how
people's genetic make-up affects their response to medicines. Because each person metabolizes drugs differently, it can take a lot of trial and error before a doctor will find the right drug or combination of drugs and dosage(s) for a particular patient. Scientists continue to find genes that regulate the metabolism of drugs. Discovering the genetic profile of how a patient may react to a class of drugs will facilitate the doctor’s decision on which drug and what dosage is appropriate for that patient. Recently, a sales representative showed me a microarray DNA chip that tests the genes responsible for the metabolism of psychiatric drugs. This test will provide psychiatrists with valuable information, so they can better prescribe medications, increasing effectiveness and reducing side effects.
Prenatal diagnosis of the unborn, using genetic testing, is always an ethically sticky subject. There are several immoral uses of prenatal genetic testing that I address in Unethical Uses of Genetic Testing, but, as Catholics, we cannot automatically assume that prenatal genetic testing is immoral. An obstetrician opposed to abortion once told me that, in his observation, genetic testing has often prevented a couple from aborting their child. He said that not knowing is often more scary than knowing, and couples may be more likely to abort if they do not have all of the information available. In the future, with the perfection of surgery on the unborn in the womb, prenatal genetic testing may actually save unborn lives. The Vatican Congregation of the Doctrine of the Faith has made a statement on prenatal diagnosis:
“Is prenatal diagnosis morally licit? If prenatal diagnosis respects the life and the integrity of the embryo and the human fetus and is directed toward safeguarding or healing as an individual, then the answer is affirmative.”All of the benefits of genetic testing are too numerous to list here. The Catholic Church welcomes genetic testing when its function is to improve sound medical practice. The possibilities of genetic testing prompted John Paul II to make the following statement:
Indeed, the biomedical sciences are currently experiencing a period of rapid and marvelous growth, especially with regard to new discoveries in the areas of genetics…. But if scientific research is to be directed toward respect for personal dignity and support of human life, its scientific validity according to the rules of each discipline is not enough. It must also qualify positively from the ethical point of view, and this presupposes that from the outset it endeavors to promote the true good of human beings as individuals and as a community. This happens when efforts are made to eliminate the causes of disease by putting real prevention into practice, or whenever more effective therapies are sought for the treatment of serious illnesses.
Thursday, September 25. 2008
A mouthful, but certainly a step in the right direction. From LifeNews:
On Tuesday, the Senate passed a bill via unanimous consent that is designed to help reduce the number of abortions of babies with Down syndrome and other conditions....
Wednesday, September 24. 2008
Genetic testing is a very powerful tool. Done properly with the right counseling, it can mean healthier and prolonged lives for many patients. For example, variations in the BRCA gene are a predictor for breast and ovarian cancer. Men and women with a family history of breast and ovarian cancer often want to get tested for this variant. If they test positive, many will alter their behavior, like quiting smoking or halting the use of birth control pills. Some will even under go prophylactic surgery removing breast and ovarian tissue to prevent the development of cancer.
Usually these patients are consenting adults who are over 25. They can understand the implications and act appropriately. But what if a parent tests positive for a inherited predictive gene and wants to test their child? Is 18 old enough? What about 16? Would it shock you to know that some parents test their children for cancer predicting genes as young as 4?
The AP has a great piece on the implications of testing children too early. What is too early? It depends on the clinical relevance of the particular test. If those who have the BRCA variant rarely develop cancer before the age of 25, then what would be the point of genetic testing for a 4 year-old? If there is nothing that is to be done until the child is older why burden them the information?
Here are some reasons given to test a child:
Yes, information is a good thing. But can't the parents of these children warn them about risky behavior without getting the test done? Then the child can choose for themselves if they want the genetic information or not. My father warned me that his side of the family had a history of alcoholism. I didn't need a genetic test to avoid heavy drinking.
The major concerns with testing children are the ethical and emotional implications. Can a child really give informed consent and is the information too much for them too handle?:
So the American Society of Clinical Oncology and other groups say that when the risk of childhood cancer is low and nothing can be done to lower it, children should not be given gene tests.
Hear hear! And this is why I agree:
Genetics is rarely 100% predictive but in this age where science is king, children and young adults may feel that they have been handed a genetic death sentence. This may also effect their plans for children and family:
If you or someone you know decides to test their children for cancer or other predictive genetic tests, all I can say is counseling is critical. Do not take the test results, stick them in a drawer and then live in guilt and fear. Take them to a genetic counselor and get informed!
Hat Tip: Bioethics.com
Thursday, September 18. 2008
UK doctors are estimating that two normal fetuses are miscarried for every three Down syndrome fetuses that are detected. Here is a perfect example of genetic testing gone horribly wrong. Genetic testing can be a positive thing, except when it is used for a "search-and-destroy" mission. From the Telegraph:
"Prevented from being born" Wow. That certainly is a nice way of saying "ripped out of mother's womb and killed for having an extra chromosome."
Hat Tip: Wesley J. Smith
Thursday, June 19. 2008
There has been a lot in the news lately about how California Health officials have ordered 13 genetic testing companies to stop testing California residents. I think many people do not understand why public health officials are concerned about the flood of new genetic tests offered directly to the public. I think I have an example that may illustrate the problem.
Cystic Fibrosis (CF) is a devastating disease that is caused by mutations in the CFTR gene. To have CF, you must inherent one mutation from your mother and one from your father, which means that both copies of your CFTR gene do not work properly. If you only have one mutation in your CFTR gene you are called a carrier for CF, which means that while one copy of the CFTR gene isn't up to snuff, you at least have one working copy. The one working copy is enough to prevent you from developing CF symptoms.
But, being a carrier is no picnic because if you were to have a child with a person who was also a carrier, there is a 25% chance that child will have CF. Most CF carriers have no idea that they carry a mutation in their CFTR gene. About 1 in every 30 North American caucasians is a carrier.
So that brings us to the I148T mutation. When researchers were studying the causes of CF, they discovered that there were a significant amount of people that had CF that also had a mutation in the CFTR gene that causes a substitution of a threonine amino acid for an isoleucine at position 148 of the CFTR protein. Hence the name I148T. Researchers made the assumption that the I148T was one of the two mutations that caused the patients' CF.
So, anyone who was found to have the I148T mutation, but did not have CF symptoms was labeled a carrier for CF. The I148T mutation was included in the testing panel for many labs, including mine.
Unfortunately, that isn't the end of the story. As more people were tested, researchers found that there were people who had the I148T mutation with another known mutation, but did not have CF. If the I148T mutation was actually was a disease causing mutation, then these people should definitely have symptoms of CF, but they did not.
What researchers eventually found was that I148T was actually what is called a benign polymorphism, which means that it is a mutation that does not cause disease. What they found was that the disease causing mutation is really a deletion of 6 base pairs at nucleotide number 3199. The mutation is called 3199del6 and just happens to be inherited in high frequency with the I148T mutation.
Long story short: Lots of people were told they were carriers of a CF causing mutation, namely the I148T mutation, when actually, they just carried a benign polymorphism. Time and more information revealed a more complex picture of CF mutations. To this day the I148T is on the CF testing panel in commercial CF testing kits. We used it as a flag to conduct further testing for the 3199del6 mutation.
So the lesson is, just because a mutation is present does not mean it causes disease. Any genetic test has to have a mound of research proving that it has any clinical relevance. A reputable genetic counselor would be able to sift through the data and give you an interpretation of your results.
Tuesday, June 17. 2008
Genetic testing is an amazing thing. It can provide such valuable information while at the same time confusing the heck out of everyone including your doctor. The question isn't just whether or not a genetic test is accurate, but whether or not the test has any clinical relevance. In other words, so your test says you have a certain mutation, is there sufficient evidence to show that that mutation may have a impact on your health? If the test is brand spankin new, offered by some internet start-up, I wouldn't trust it. If you want to order genetic testing online for yourself, go for it. Knowledge is power, just be aware that you are going to have to do some serious digging to make sure you know what your test results really mean.
California authorities have recently ordered 13 companies to halt genetic testing to CA residents until said companies can prove they are in compliance with California state law. From the San Jose Mercury News:
Friday, June 13. 2008
That is the question that finally seems to be getting the attention it deserves. From the Technology Review:
Most people do not realize that many docs do not the implications of genetic testing. Genetic counseling, people! I cannot stress it enough. Without a proper interpretation, results of a genetic test might as well be a book written in Klingon.
Good for Coriell for addressing the issue. But those of us in the testing field know that Coriell is a great place to purchase hard to get cell lines or DNA. 10,000 volunteers offering up their saliva for genetic testing. For free. I am wondering if the volunteers of this study know or understand that their DNA maybe listed on the Internet (anonomously of course) for order by labs across the country. I hope so.
Friday, January 11. 2008
Before I begin this entry, I want to give my sincere apology to any of my readers that I have abandoned over the last several months. For many reasons I was unable to blog. And it always weighed heavily on my mind. A fight is gearing up in my state on assisted suicide and I have been trying to get myself ready to speak out on that issue. Also I have acute seasonal affective disorder that sometimes just makes it hard to get dressed in the morning. I need to move back to California!!!
Now that it is 2008, I have vowed to keep on keeping on as best I can. So I am starting with a relatively easy one, autism.
There has been much hoopla about what causes autism, is it genetic? Is it caused by a reaction to routine vaccinations?
The signs are pointing to genetics as a cause. In my very limited experience with austism genetic testing, my lab tests two genes that has been shown to cause autism (MECP2 and Fragile X), I finally had an "Ah-Ha!" moment. Mutations in MECP2, which is on the X chromosome, do not start rearing their ugly heads until a girl (boys don't usually survive full-term) is around 9 to 12 months. So parents have a normal child and then all of a sudden she begins to digress and starts showing signs of autism or Retts syndrome. That is also the very time she is getting her vaccinations. I am no expert on the issue, but it seems to me that blaming vaccinations would be an easy mistake to make.
A new study in the New England Journal of Medicine shows that autism has a genetic component. From US News and World Report:
The upshot? Do not fail to vaccinate your children just because you think it might cause autism. You may be doing their health a disservice.
In the next few decades, you as consumers will be inundated with genome services that will claim that they sequence your genome and then can tell your future bases on your genes. Is it a scan or a scam?
Thursday, September 20. 2007
This study published in the Journal of the American Medical Association does not surprise me, but it has some serious lessons to teach. Lessons that genetic professionals and patients a like need to hear.
The study found that some couples choose abortion after receiving information that their fetus has a genetic disorder, even though that genetic disorder does not cause serious health problems. From The Houston Chronicle:
So the question is: is it appropriate to prenatally screen for nonlife-threatening diseases?
Initially, it would seem that the answer would be "NO" if couples are running out to abort children that are even the slightest bit defective. But I think that "NO" is a knee-jerk reaction. Let us consider more facts from the study:
So, those couples who were more informed and had counseling from professionals were MUCH less likely to abort. Those couples who were given the test results and left to fend for themselves, got scared and aborted. Genetics can be scary and professional counseling is critical for proper interpretation of genetic test results:
Dr. Joel Charrow of Children's Memorial Hospital in Chicago, who treats patients with Gaucher disease and counsels carrier couples, said he doesn't know of any terminations among parents he spoke with about the condition.
The Catholic Church is very clear on prenatal testing. It is a good thing, unless it is procured with the specific intention of aborting upon an undesired result.
This study shows that we need more information and more qualified genetic counselors to help couples deal with an unexpected and possibly scary prenatal test result. If you, or someone you know, has had such a prenatal genetic test result, point them to the nearest genetic counselor pronto. In the interim, Be Not Afraid is an excellent online resource.
Finally, this study makes me give kudos to Senators Brownback and Kennedy for pushing their legislation the Prenatally and Postnatally Diagnosed Conditions Awareness Act which:
Monday, September 17. 2007
Here is a long overdue update on the world of pharmacogenomics. You should care about pharmacogenomics because how you metabolize the drugs your doctor prescribes is encoded in your DNA. Pharmaco (drugs) + genomics (genetics) = personalized medicine. If your doctor knows how you metabolize certain drugs then he (or she) can choose the right medication for you at the right dose without so much trial and error. Any of you who have been diagnosed with depression, anxiety or obsessive-compulsive disorder know exactly what I am talking about.
This article from the San Francisco Chronicle has a great synthesis of all the latest in pharmacogenomics.
First up: nursing moms ACHTUNG! You need to be very aware about the condition of your newborn if you are taking codeine for pain. Most of us metabolize codeine into morphine at a normal rate. But a very few of us, depending on our genetic make-up, ultra-rapidly metabolize codeine into morphine which gets into the breast milk and can be bad for baby. In one case it was fatal:
Next up: breast cancer. The test that would screen mothers to see how they metabolize drugs is a genetic test for variations in the gene that codes for a liver enzyme called CYP2D6. The CYP2D6 liver enzyme is envoled in the metabolism of many common drugs including antidepressants. So one CYP2D6 genetic test could tell your doctor how to prescribe all kinds of medication for you. One case would be which drugs should be used to treat breast cancer:
And finally, blood clots. Warfarin, or Coumadin, is a commonly prescribed blood thinner to prevent blood clots, heart attacks and strokes. To little and it has little effect, but too much could cause fatal internal bleeding. And guess what, there is a genetic test that would help doctors correctly dose their patients:
The FDA advised doctors to
So do not be surprised if in the near future before your doctor takes out his prescription pad, he pulls out a Q-tip and starts swabbing the inside of your mouth to see what your genes have to say about the way you metabolize drugs.
Monday, March 19. 2007
This piece from the New York Times is very interesting. It is about Huntington's disease, one of the most tragic genetic disorders. Unlike a lot of genetic disorders that are recessive, the genetic cause of Huntington's is dominant, which means that if you inherent the variant that causes the disease, you will develop the disease.
This heart-breaking story is about Katharine Moser, a young woman that has not only been given a positive test result, but also that her variant causes early onset of the disease. She expects to begin showing symptoms of the incurable brain disorder at age 37.
The reason this piece is so well done is that it rightly points out the impact of Ms. Moser's diagnosis not only on her, but on her entire family. Because Ms. Moser tested positive, her mother knows that she also carries the Huntington's variant and her mother didn't want to know.
Read the whole thing because it gives a clear picture of the pros and cons of genetic testing. But what I want to highlight is the reaction of a counselor to Ms. Moser's diagnosis:
Her moral and ethical obligation not to have children. Nice. This is how far we have come. I will not be surprised if someday there is legislation that says it is a crime to have a child with Tay Sachs, or cystic fibrosis, or one that will get Huntington's.
Some people may find the counselor's advice sound. But it contains one fatal flaw. There is no hope or thought for a cure. Ms. Moser future children may have 40 years to live a normal life in which time a cure or treatment may become available.
This is the down side of genetic testing in our society. The immediate thought that just because something is genetic, it is inevitable and if there is no cure now, there will never be one. Sad. Very, very sad.
Tuesday, March 6. 2007
Monday, February 26. 2007
Boy, have I dropped the ball, and it shattered. I have been properly scolded by Jay for not blogging about the Discovery Channel's documentary "The Lost Tomb of Jesus" which suggests that researchers have found Jesus and his family in a family tomb:
Oooooh, they have brought out the big guns: DNA analysis. I can't possibly do a better job than Darwin Catholic analyzing this "breakthrough" so I won't try, but I will stress one very important point:
I likely use the same human identification kit in my lab that these researchers used, and unless you have a sample from the individual of interest, in this case Jesus himself, there is no way these researchers can know that this DNA sample is from Christ.
They can tell that the individuals in the tomb are not related and have an offspring together, but there certainly is no label in the DNA that says "Property of Jesus Christ" on it.
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