Interviewer: 60 Minutes presents a live interview with Professor Bob Williamson to talk about medical genetics.
Interviewer: Professor Williamson thank you for talking to us tonight, in our live online chat room.
Prof Williamson: Hello everyone, welcome to the website and I’m glad you are interested enough in this topic to log on and ask question. From my point of view, the important thing is that this is information that is helpful, but most of the time is only indicative of high or low risks and so you can really use the information to try and alter the way in which you live in your environment to make things better.
Pete asks: What is genetics?
Prof Williamson: Genetics is the study of the characteristics, things that parents pass on to their children. It works through DNA, which is a chemical that works in the nucleus, in the centre of every cell in our body. When a sperm hits an egg cell, it meets the genes of the mother (from the father), it comes the genes of the children. It is very important in determining how we look, how our bodies function, the fact that our arms are the top of our body, but it also helps determine health and diseases, but it is not everything. It can also be influenced by our diet and environment.
Nelso asks: How are the DNA samples collected?
Prof Williamson: Every cell in our body has the same set of DNA instructions, whether it is blood, brain or skin cells. Because of this, you can get DNA from any cell and usually if you’re doing a test, you’d collect skin cells from the inside of the cheek by rubbing a brush against it, and this is because it is very easy and doesn’t involve a Doctor of a Nurse taking a sample. If you need a lot of DNA (because the test is difficult) you might get a blood sample, and often for really important accurate DNA tests, a blood sample will be taken.
Poppie asks: Does genetic testing really make a difference if I already know I have a family history of cancer?
Prof Williamson: It can make a very big difference in some cases. For instance, if you have a strong family history for bowel/colon cancer and the Doctors find out that one of your parents who has colon cancer has a particular mutation, you only have a 50% change of inheriting it. And under those circumstances, finding out you have the mutation, will mean you want to get tested regularly.
However, if you haven’t inherited the mutation, you don’t have to worry about it. But I must emphasis that this is only for a small group, where there is an extremely strong family history. Most cancers can come from 5-10 genes working together, plus the environment. Even if you have a high risk cancer gene, you can change the environment to lower your risk. E.g.) if you have a high risk gene to skin cancer, stay out of the sun and you minimize your risk.
Lucy asks: If genetic testing makes such a difference, why hasn't my family doctor recommended it to me before now?
Prof Williamson: Genetic testing is very new and it’s expensive and it’s not available in Australia from an Australian supplier. This means that anyone who wants a genetic test has to go overseas and not all of them are controlled as rigorously as an Australian company would be. Also, many doctors feel that a family should only go through the tests if they have a medical advisor or a geneticist explain the significance to them. e.g) many of the things in the reports that we received where not important at all and I just explained to the guest that being told that you are at 1.1 or a 0.9 risk doesn’t have any significance. I thing many doctors are worried that many families will become overly concerns over information they don’t fully understand. I’m amongst the group of geneticist that is more supportive because I’ve seen the difference this can make and also I believe the information can be used by people to improve their environment and reduce the risk of these diseases. Of course, if it were really bad news, you would need to go to talk to your Doctor about the results and indeed if you are at risk of a serious genetic disease you can already go to your Doctor and receive free care anywhere in Australia.
molly323 asks: If I have a test done and it shows cancer in the genes. Does that mean cancer will kill me, if nothing else does of course?
Prof Williamson: The important thing about genetic information to know is that it usually gives you the opportunity to change your behaviour, your environment or your medical intervention to reduce your risk. E.g.) if you found you had a gene that meant you had a high risk of colon cancer you could have a test every 12 months to locate cancers before they became large enough to create problems and you would be likely to survive. If you didn’t know, you might not have the tests, and a cancer might well grow to a point it was untreatable before you knew it exists. The real value is that it tells you when it is worth either seeing a doctor or changing your lifestyle or both.
simon asks: Hi Bob, can these tests tell you something your family history can't?
Prof Williamson: The test can tell you things you family history can’t, and an example is in for cystic fibrosis, a seriously genetic dieses that affects children that I’ve worked on for 30 years. It is a disease where a child has to inherit the mutation from both parents. The parents, who are carrier and have one copied of the unaffected gene and one of the mutation are completely healthy. There are 1 million healthy carriers in Australia, and it’s only when two carriers marry and have children that there is a risk of having a child who is affected. The gene test will tell you whether you are a carrier, even if you are completely healthy. If you are married to another carrier, this is good information to know so you can either have a pre-natal test or prepare yourself for offer the best treatments to your child.
Mick asks: Who can gain access to my genetic test results?
Prof Williamson: That’s a very important question. If you send a sample yourself, to one of the overseas gene testing labs, what you do with that information is, offcourse, up to you. However, if you apply for insurance and you have had a gene theft that shows you are at high risk of some disease or other, you do have to tell the insurance company that you have had the test. However, an insurance company cannot insist you have had the test; it is completely up to you if you have the test or not. In the same way, it is no possible for you husband, wife, children to insist of knowing the results of the test unless you want to tell them. However it does make sense to discuss any medical results with your Doctor or with a geneticist because they are most likely to help you to interpret how important the test is.
TERRY asks: How much does it cost for the DNA testing ? How do I know it's not fake?
Prof Williamson: The price of the test has been coming down, and I believe the cheapest total DNA test is (for all variation on every chromosome) at almost 100,000 sites is about $400. However, if you wait for 3 months, it will probably come down to $250 because the companies have a great deal of capacity because of the machinery is very powerful and works fast. There would be no reason for anyone to offer a fake test, because the machine are automated and the companies feed the sample into one end of the machine and get the computerise read out from the other. If the data were fake, people would find out very soon since some of the tests that are done identify mutations that would follow up by Doctors, and if they did not agree, the companies could be sued.
twodogs100 asks: Hi Bob, I’m keen to get tested, what is the best kit to buy, or who gives the best results? Anyone in Aust doing it?
Prof Williamson: No one in Australia is doing it yet for all the chromosomes, but offcourse many labs are testing for particular genes for common mutations. If you want a complete scan you have to go overseas, there are many companies now offering this test of which the best known are Decode, 23andme and Navigenicf. There are a few more, but I think that all the companies are fairly similar, and if you search for them on the internet, you can have a read and see which one offers the best value and the most comprehensive service for you.
zac001 asks: Do you need a genetic expert to interpret the report?
Prof Williamson: The reports contain a lot of information about risks, and most of the information is really very simple to understand. If you have a high risk of a disease which is fairly uncommon, your risk might still be very low because the disease is rare. If I were to criticize the material that was sent out on the show, it would be because it didn’t make it clear which results was really of most interest, and which were trivial. To tell someone they have a tiny increase or tiny decrease risk of a common disease (heart attack) doesn’t really help. The report also should have given a clearer idea of the meaning of results if someone is a carrier of a disease, as carriers are company healthy and are only at risk if they have having children with another carrier. However, although a Doctor or geneticist might help someone to understand the information, I don’t think the average intelligent member of the community would have much trouble.
andrea_f asks: Do you have to have reached a certain age before undertaking the test? I have a 16 year old daughter- should I be thinking/encouraging her to have the test?
Prof Williamson: In Australia, a test would not be offered to someone under the age of 18 unless there was a very good reason. Usually someone has to be over 18 before they can be tested. However, if you are thinking of a gene test from one of the overseas gene testing companies, they may take a sample from anyone although they probably would rather take it from people who can decide for themselves. However, unless there is a really good genetic reason, just as a family history that very strong, it might be best to wait and let your daughter decide for herself when she is a bit older whether she wants the test or not. That would have the added advantage that we would have a much better understand of what information can be obtained from the test, it is important to remember that the tests are extremely new, as they have only been around for 1-2 years and we are learning new information all the time that increases the value of the data that are obtained.
simon asks: Hi Bob - could you see the accuracy of DNA testing potentially changing the ability to maintain life insurance, or is it alone not conclusive?
Prof Williamson: The DNA tests is completely accurate; it’s the interpretation that sometimes raises problems. When it comes to life insurance there are a small number of cases where a DNA test is very important. E.g.) a small number of breast cancer cases (1-3%) are due to a single gene, such as BRC1. In a case like this, knowing whether you have the gene or not, and there is only a 50-50 change of inheriting the gene is absolutely critical, and knowing this information would have a major impact on your life insurance. However life insurance companies in Australia, but not in other countries are compelled by law to give evidence when they sue genetic data, and in some cases they have been extremely positive about genetic testing and do not discriminate against people provided they enter into the best available medical program to lower their risk.
Graham asks: Hi Bob. Are we far away from seeing a genetic test for clinical depression? Does research to date primarily implicate serotonin in the aetiology of depression or is there another focus? Thanks.
Prof Williamson: The brain and its function are of great unknown in medical science. We know the genes interact with the environment to determine risk of depression, and we know that some of the genes affect serotonin metabolism. But there are other genes involved as well, as well as environment. As for now, there is no clear pattern that can be used to predict whether someone is likely to develop depression, nor whether they can be treated by one class of drugs or another, or by one form of therapy or another. The reason for this is that we can find out what is going on genetically and biochemically in the blood, in the liver and on the skin, but we cannot work out what is going on inside the brain with any degree of accuracy. I have no doubt that the interactions between genes and environments that determined risk of depression can be worked out in the next 20-30 years, but it is not around yet.
Jacasp asks: Grandmother had Alzheimers as does my Mother, probably a good idea for me to get checked?
Prof Williamson: Not all geneticists agree on this one, but I personally think that it is useful for people to know if they are at high or low risks of developing Alzheimers. If your family history indicates a high risk, there is still only a 50-50 chance that you have the gene that often gives this higher risk. However many geneticist don’t think the test is accurate enough because only 1/3 that have the gene develop Alzheimers before they are 80. People who don’t have the gene are very unlikely to develop Alzheimers before they are 80. It is up to you and your Doctor, but if you have a family history that leads you to be concerned about this, perhaps you should have a chat with the Doctor who cared for your mother and see whether he/she thinks that a test would be worthwhile.
Flutters asks: As an adopted child I found when I met my birth parents that much of my mannerisms etc were the same as my biological parents, and not something I could have "learned" from them. Do you agree that not just medical conditions are inherited by genes, but also behaviour?
Prof Williamson: Sure do, you don’t have to be a geneticist that we inherit much of our behaviour from our biological parents. It used to be thought that environment determined behaviour but we now know that genes are now more important than environment, particularly from studies from identical twins who were separated at birth. However, it is not all genes, anymore than it is all environment, for instance, you have inherited wonderful musical abilities, but if your adopted parents never listen to music, you are unlike to become a musician. There are many things in behaviour that are determiner genetically, but only express themselves when the environment is right.
alan asks: How broad is the testing what are the big ticket items that this does not cover?
Prof Williamson: The testing looks at genes on every chromosomes and focuses on cancer, heart diseases, eyes diseases and Alzheimers, It also has the potential to tell you whether you are a healthy carrier for particular diseases. However it is very very weak when it comes to looking at mental health and conditions such as depression and schizophrenia, and I thought that the information that we got back on the show was a bit misleading when it talked about overall risks, such as diseases for lung cancer which is actually more an environmentally influenced disease. The gene test will only be of more valuable when we understand the interaction between gene and environment and susceptibility to infection. For instance, I’m interested in why only 10% of people who are exploded to swine flu in a plane come down with the diseases. This could be a mixture of genes, but why?
Harry asks: Hi Bob, While watching I was not convinced of the usefulness of this DNA information you can provide. Informing people they have the population average chance of having a disease is not any more helpful than my insurer informing me I have an average change of having heart disease. I feel these tests are just a way for genetic companies to bank roll their expensive research. I say this because the results you provide can’t be proven, if Lane Beachly gets or doesn’t get Alzheimer’s will she remember the test she took? Will she remember that she had a high chance? Regardless of the outcome telling people they have high, medium, or low POSSIBLE chance removes Geneticists from any responsibility. If you want your genetic research to help people, you need to provide yes or no answers. Tell me yes you will get heart disease, or no you will not get cancer, until your tests can say that all you’re doing exploiting people's uncertainty for monetary gain.
Prof Williamson: Can I first say that I personally do not have anything to do with the genetic companies. However that doesn’t mean your point isn’t important, the companies are interested in turning a dollar and certainly over sell the significance of the data. However, some of the information really is useful, if someone comes from a high risk colon/breast cancer family, the test can establish whether they personally are at high risk, or whether the same risk as the average. In the same way, the test will tell the one person in 200 who is at an extremely high risk of haemochromatosis, that they carry the mutation on both chromosomes. This is potentially life saving information. It may be that only 5% people test will receive such information, but for those people, the information is extremely important. For the rest of us, the value of the tests to some extend is reassurance. Is this worth it? That varies from individual to individual, but it is information that I would like to know, not as a geneticist. I should add that the companies don’t actually do much genetic research and the genetic research is funded by government agencies, the NHNRC, NRH in America rather than by companies.
Interviewer: Unfortunately, we are out of time, do you have anything else you would like to share before we finish tonight?
Prof Williamson: Thanks very much, I’m pleased that so many people have taken an interest in our genetics and genetic testing, and with the human genome project it is obvious this will be of importance for the next 10-20 years.
Interviewer: Once again thank you and goodnight.
Interviewer: This concludes our chat with Professor Bob Williamson, Sunday May 31, 2009.
