What is genetic testing?
Genetic testing is the scientific testing that can identify changed or abnormalities in chromosomes, genes or proteins. This type of medical test is done for an individual with a suspected genetic disorder. Genetic testing can be used to find faulty genes that can cause certain diseases such as cancer to develop. There are several types of genetic tests such as Diagnostic testing which is used to identify the disease that a person may already have. Predictive genetic testing is tests are used to examine changes in genes that may increase the risk of developing a disease. Another example is the carrier test ,which is aimed at people who may carry a gene that is related to disease. Often, these types of tests can be categorised into three sub tests, known as molecular genetic tests, chromosomal genetic tests and biochemical genetic tests.
How is it done?
Genetic testing is usually recommended by a doctor for a person suspected of having an increased chance of getting a particular disease or condition due to their family history. Genetic tests are primarily performed on samples of blood, hair, skin, amniotic fluid or tissue samples that are sent to a laboratory specialising in genetic testing. The specialists looking at this sample analyse the chains of DNA at several different locations and inspect them for mutations that can be related to the subjects suspected medical condition. After several weeks of the results being compared against hundreds of known diseases, the results are sent back to the person showing the results of the genetic testing. There are alternative ways to have genetic tests done such as online genetic testing. This method however is not recommended for security reasons as there is no guarantee that a person’s information is kept private, and in addition it does not allow the person do discuss results and decisions directly with the doctor or professional.
¥ Newborn screening
Newborn screening is used just after birth to identify genetic disorders that can be treated early in the early stages of life.
¥ Diagnostic testing
Diagnostic testing is used to identify or rule out a specific genetic or chromosomal condition. In many cases, genetic testing is used to confirm a diagnosis when a particular condition is suspected based on physical signs and symptoms. Diagnostic testing can be performed before birth, anytime during the pregnancy or at any time during a person's life, but it is limited to specific genes and not available for all genetic conditions. The results of a diagnostic test can influence a person's choices about health care and the management of the disorder, and also help to improve future health prospects.
¥ Carrier testing
Carrier testing is used to identify people who carry one copy of a gene mutation that, when present in two copies, causes a genetic disorder. This type of testing is offered to individuals who have a family history of a genetic disorder and to people in certain ethnic groups with an increased risk of specific genetic conditions. If both parents are tested, the test can provide information about a couple's risk of having a child with a genetic condition.
¥ Prenatal testing
Prenatal testing is used to detect changes in a fetus's genes or chromosomes before birth. This type of testing is offered during pregnancy if there is an increased risk that the baby will have a genetic or chromosomal disorder.
¥ Preimplantation testing
Preimplantation testing, is a specialized technique that can reduce the risk of having a child with a particular genetic or chromosomal disorder. It is used to detect genetic changes in embryos that were created using assisted reproductive techniques.
¥ Predictive Testing
Since the marker gene for HD was discovered in 1983 it has been possible for an "at risk" person 18 years or over to have a predictive test. Deciding whether to have the predictive test is a very personal choice. It needs to be considered carefully because the implications vary for each person.
¥ Prenatal Predictive Testing
There is also a prenatal form of the predictive test for HD. The purpose of prenatal testing is to screen the fetus in order to avoid passing on the HD gene to the next generation. If the fetus is found to have a high risk of carrying the HD gene, the option weather or not to terminate the pregnancy can be chosen by the parents.
¥ Pre-implantation Genetic Diagnosis
Pre-implantation genetic diagnosis is new form of prenatal testing that utilizes advanced reproductive technology. It avoids the need for termination of a pregnancy where the fetus has inherited the HD gene. The testing involves creating embryos in vitro a test tube. The embryos are then tested to see if they have the defective gene. Only embryos which do not have the defective gene are then implanted in the female partner who it is hoped will become pregnant.
Who has it done?
Genetic testing is generally offered to people who have a family history of a certain disease known to be associated with genetic mutations. Genetic mutation is where the DNA sequence of a gene is altered. This can have varying effects on health where it can be beneficial, although in some cases it can be very harmful. Inherited mutations would give the same faulty genes to people and therefore could cause the same diseases carried by the parents. However, while inherited mutations contribute in 5 to 10 percent of diseases, other factors such as lifestyle, surrounding environment, and or drugs can play a large role.
Why would you get it done?
The results of a genetic test can accurately identify a disease and give precise information on genetic changes. This can then be used to determine the patients future medial needs. Knowing the results of a genetic test can change peoples habits, lifestyle or healthcare to improve future health prospects. Parents (or future parents) may consider getting tested so they can decide weather to have children., or to make sure their children will be healthy. Parents who carry a gene related to a disease could pass it onto their children. Carriers of a gene may not show any signs of the disease but can pass it on to their offspring, who then have the chance to develop the disease.
How can this information be used against you?
Many businesses rely on genetic testing to choose their employees. People that suffer from genetic mutations and diseases run the risk of having a lower chance and getting a job as insurance comes into play it can become an issue as it directly affects your finances and companies can afford to charge higher premiums or even refuse to offer you insurance.
Arguments in favour genetic testing
¥ If there is a family background or history with a certain disease, you would want to know weather you will pass it on to the next generation, or weather you carry it yourself.
¥ If you are able to see similarities in yourself and you have symptoms of the disease it can put you at ease knowing weather or not you carry the disease or genetic mutation.
¥ If you get tested and you find out you do have a condition that has no cure you will live life to the fullest, and If you don’t you can pursue other interests.
¥ Getting your children tested while they are in the womb and the result being positive can determine whether or not you would terminate the pregnancy so your child did not grow up with a horrible life.
Arguments Against genetic testing
¥ If you have the test and its positive I have still got the worry of when the gene will kick in.
¥ If there is a gene that there is no cure for in your family there is nothing you can do about it so why put yourself under that mental stress.
¥ If you already get other things done such as ultra sounds and MRI’s that can tell you if you have an illness, what is the point of genetic testing?
¥ People still want to hope that they don’t get the conditions and getting genetic testing can ruin that hope
Gary Lovell’s family suffered from early onset Alzheimer’s through 5 generations. He first heard about this problem from his mother. “When my mother first got sick, she was 50, so she sat me down and said, "I hope you don't get this", I didn't know what that meant, I later found out about the whole family tree and that went back four generations.” Gary tested positive for the gene, the same gene as his mother, therefore meaning that he will suffer from Alzheimer’s disease early. This result influenced Gary and his wife’s decision to have children. Jenny Brockie, Gary’s wife spoke about this. “Yeah, look, that was probably the biggest issue. Garry had always said if he has this condition he never wanted to pass it on, to any children. So, that sent us on a quest to come up with some sort of other solution to having children, so we looked at things like adoption and sperm donorship, it was when we were doing, looking at sperm donorship that we came up with the option for us now to test any embryos, because they have found the gene responsible.”
• Garry had a genetic disorder from 4 generations back
• Garry has the gene from his mum and will get Alzheimer’s
• Garry and Mandy not sure to have kids because Garry doesn’t want to pass on but scientists have developed tests and identified the genes responsible for Alzheimer’s
Alzheimer’s disease is the most common form of dementia, effecting up to 70% of all people with dementia. The disease damages the brain directly, which results in impaired memory, thinking and likewise behaviour.
The newest blood test to detect Alzheimer's may be able to predict the disease 10 years before symptoms occur with 100% accuracy. Researchers from the National Institute on Aging are focusing on a protein in the brain called IRS-1 that may signal the earliest stages of Alzheimer's
A progressive disease that destroys memory and other important mental functions.
It cannot be cured, although medication can lessen the suffering of the patient and make the effects less detrimental.
Jason and Melissa’s father suffered from a genetic condition called spino cerebella ataxia. He got this illness at around age 35 when he was tested. “…mum and dad noticed that his movement was slightly impaired. His father had the illness as well, so gradually from the age of about 35 to 50 the illness gradually became worse and worse and the basic symptoms impaired movement, it gets worse and worse, and some people almost compare it to mild drunkenness and then, yeah, he passed away the beginning of the year.” Jason and Melissa both had a 50% chance of carrying this disease, and therefore both decided to get tested for the gene. Melissa was tested positive for this gene at age 18, and this changed the way she viewed her life and she claims this gave her the ‘courage’ to travel. Jason on the other hand took the test at 21 years and was tested negative.
• Jason Gordon affected by SCAR and his dad got the illness when he was 35
• Jason’s grandpa had the illness as well
• Symptoms include impaired movement (rapidly deteriorates)
• They compare Scar to mild drunkenness
• Melissa thinks it has made her stronger because she has made friends she wouldn’t have made
• Jason waited because he thought that he didn’t have the maturity to deal with the fact he might have the illness (Tested at 21 and Melissa tested at 18)
Lorrice’s mother, brother and sister all suffered from a hereditary incurable condition, motor neurone disease. Lorrice has a 50% chance of having the disease, and there are no cures for it, she has decided against being tested.
• She didn’t want the test because there wasn’t a cure for motor neurone disease and she was a little scared of receiving the news she was positive
• She had a 50-50 chance to get and she just didn’t want her mental stress to go any higher than it was
• Both her siblings died of the disease
Krystal’s family has previously suffered form breast and ovarian cancer over many generations. “…my great grandmother died of breast cancer at 68, my grandma was 44, she had an occurrence again at 53, my mum was 36 and over our extended family, there's well over 20 women that have been affected or either died from breast and ovarian cancer the youngest was 35 from breast and 37 from ovarian cancer.” Krystal took the test when she was 22 and after having her first child. “it was positive, so we are BRCA1 positive, which gives you anywhere up to a 90% chance of breast cancer and 50 or so % chance of ovarian cancer…” She then took the risk of having another child, “so I had another child and I had two boys, which I held in my belly for months praying that I had boys. “ She then decided to have a preventative double mastectomy when she was told she had signs of early breast cancer. Another reason for her decision was because she did not want other people watch her go through cancer. Her grandmother, who had breast cancer said, “We were like Krystal, very positive about it, I didn't want to see her go through having breast cancer and worrying her life with thinking about will I be here for my little boys.”
• Now possible to test 400 genetic diseases
Jackie “Before she was married, Jackie’s husband told her the debilitating Huntington's disease ran in his family. His Mother had it but he said he was tested for the gene and the test was negative. They went ahead and had two children, who are both now under four. Then two months ago Jackie found out her husband lied. He had in fact tested positive for the Huntington's gene a decade ago.” Jackie’s husband did not tell her the truth in fear of losing her. “He didn't want to lose me. He said that he loved me so very much, and the very thought of me seeing him as a different person and not wanting to stay with him was worth going through what he had done with me, with the children.” Her children now have a 50/50 percent chance of having Huntington's disease.
• Jacki’s husband had a family history of Huntington’s disease and revealed to her he had been testing negative
• They had kids two who are just under 4 and then two months ago he revealed he had lied about the test
• She went into shock and couldn’t breathe properly
• He didn’t want to lose her and for her to see him as a different person
• She thinks about wanting to know but he doesn’t know if that would change the way she feels
• Would’ve been happy not to have kids if she didn’t know
• Jenna Bamborough-Lahey has a husband with the Huntington’s gene and she was told in the first week of the relationship
• Simon Turnbull (Jenna’s husband) can understand why he didn’t tell her because it’s a complex and difficult situation
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Professor Ron Trent -“When it came to testing we decided that because I had a good quality of life, my brother, who has it, has a good quality of life, that we would just continue with it, and if we passed it on, we passed it on, we've got the support mechanisms, we know that there's a lot of work being done to try to find a cure, that's a long way off and we realise that.”
Huntington’s is a hereditary disease marked by degeneration of the brain cells and causing chorea and progressive dementia.
– Nikki and her husband Andy decided not to test for the Huntington’s gene because if Andy’s father had the availability of the test, Andy would of never been born because they would have been against spreading the gene, however Andy is happy with his life and is striving.
– Melissa is for genetic testing, particularly at an early age, because it impacts your decisions for everything, and how you go about living your life afterwards.
– Jason on the other hand, waited until he was 21 before taking the test, because he felt like he wasn’t mature enough
– Lorrice decided against testing. She says she is 50% her mother’s genes, and even after the test, she will still have the uncertainty of when the disease will hit. She does not want the mental stress of knowing about the disease, and she is already aware that she has a 50/50 chance of getting it. She doesn’t feel like she needs it.
– Krystal wanted to wait until she was in the right frame of mind before getting the tests or results back. She ended up waiting until she was 22.