This lesson is called Genetic testing for healthcare and is from the unit Gene technology.

Hi, there.

My name's Mrs. McCready, and I'm here to guide you through today's lesson.

So thank you very much for joining me today.

In our lesson today, we're going to explain how genetic testing can be used to test for certain alleles associated with disease and see how this information may well be used.

Now, we're going to come across a number of keywords in our lesson today, and they're listed up here on the screen for you now.

You may wish to pause the video to make a note of them, but I will introduce them to you as we come across them.

Now, in our lesson today, first of all, we're going to have a look at how we test for alleles associated with disease before we consider how we might use these genetic test results.

So are you ready to go? I certainly am.

Let's get started.

Now, our good health may well be compromised by disease, and unfortunately this happens to all of us at various points during our life.

Now, diseases are classified into two broad categories.

Communicable diseases are those that are passed on from person to person and are caused by pathogens.

Now, pathogens include bacteria, viruses, fungi, and protists.

So these are all diseases that can be passed on and spread between us.

Now, the other category of disease is non-communicable diseases.

Now these can't be passed on from person to person in the same way that communicable diseases can be.

Instead, they are associated with factors that increase the risk of disease which are not pathogenic.

So those factors might include an unbalanced diet, lack of exercise, the recreational use of drugs, including alcohol and smoking, and exposure to ionising radiation, in particular, sun or from sun beds.

Now the thing with these types of risk factors is that they increase the risk.

So just because you have an unbalanced diet and you spend a lot of time in the sun, doesn't mean to say that you absolutely will develop certain types of diseases.

All it does is increase the risk of that occurring.

Now that means that we can do something about that.

We can change our lifestyle to reduce the risks and therefore reduce the likelihood of us developing those types of diseases in the first place.

So, for instance, we can make sure that we have a balanced diet, that we take plenty of exercise, that we avoid drinking alcohol and smoking, and that we put sunscreen on to block out sun rays when we are in the sun.

Now, non-communicable diseases can also be coded within our DNA.

So, the genetic makeup of our individual body can also directly affect our health.

So, DNA is extremely long.

It is made of many millions of bases joined one after the other, and these are then tightly wound up into chromosomes which are stored within the nucleus of our cells.

Now, within each strand of DNA, there are sections called genes, and each gene codes for a particular characteristic.

So within our genome, within our collection of DNA, there are many thousands of genes, each of which controls a particular characteristic.

So let's just check our understanding.

Which of these increase the risk of non-communicable diseases? a, lack of exercise; b, eating a balanced diet; or c, genetic information in our DNA.

I'll give you five seconds to decide.

Okay, so you should have decided that lack of exercise and our genetic information in our DNA can both increase the risk of non-communicable diseases.

Well done if you got both of those right.

Now, the human genome is made up of 23 pairs of chromosomes.

One has been inherited from your biological father and the other from your biological mother.

Now, each chromosome in the pair has the same genes located in exactly the same positions.

That's really important for our function.

So you can see on the picture there that the pink bands at the top are showing the same gene but one present on the chromosome inherited from the biologic father and one on the chromosome inherited from the biological mother.

Now, each gene on those chromosomes may be a different version of the gene, and the version of the gene is called the allele.

So alleles are versions of genes.

And you can see here on the same diagram that the version of the gene, the alleles, are different.

One is indicated with a capital B, and one is indicated with a lowercase b.

So these are different versions of the same gene where the capital B is coding for brown eyes, and the lowercase b is coding for blue eyes.

And this combination of alleles will affect our phenotype, what we end up looking like.

So let's quickly check our understanding again.

Each chromosome in a pair has an identical copy of each gene.

Is that true or false? So you should have said that that is false.

But why? So you should have explained that by saying that each chromosome in the pair can have a different version of each gene, and these versions are called alleles.

Well done if you got those right.

Now, some alleles are risk factors for certain non-communicable diseases.

So, for instance, if there is a family history of, say, cardiovascular disease, then it may well suggest that there are alleles present that increase the risk of that type of disease being inherited.

So if your father and either their mother or father both have developed cardiovascular disease, then it indicates that there may well be an allele there present within that genetic line that will increase the risk of cardiovascular disease being developed.

However, it's still only a risk.

It's not a guarantee that that disease will occur necessarily.

It's just increasing the chance of it occurring.

Now, genetic testing can be used to detect whether the alleles present within a person's genome are likely to increase risk of disease or not.

And genetic testing can be done using any sample of tissue that contains cells which store DNA.

So blood, saliva, or other body fluids can all be harvested and tested using genetic testing methods to see whether there are particular alleles which increase the risk of developing particular diseases.

Now, as well as it being an actuality in terms that the test can take place, the patient must also grant their consent, and it's not just saying, "Oh, yes, I'll have that done.

Thank you very much." But they need to provide their informed consent so they are fully aware of what is going to happen in terms of the procedure done to harvest the cells but also what those results from the test will be used for.

And that is what informed consent is about.

It's not just agreeing to the procedure, but it's understanding what will happen next especially with this kind of data.

Now the genome is made up of DNA, and DNA is made up of sequences of nucleotides.

Now, nucleotides come in four versions of bases: A, T, C, and G.

There is another type of gene technology called genome sequencing that can be used to read the sequence of DNA in the entire genome, so every single base from the start of the first chromosome to the end of the last chromosome.

Now this was first done and largely completed in 2003 by the Human Genome Project.

Now, this absolutely astonishing piece of scientific engineering and ingenuity took 13 years to complete and required international cooperation in order to be completed.

Now the Human Genome Project was the first time that the human genome had been sequenced from start to finish.

Now, 20 years later, that can be done, that same process can be done, in a few hours.

So technology has come on a long way in the last 20 years or so because a machine like ours pictured on the screen here, can be used now to read the human genome now in a few hours.

Now, genome sequencing has enabled scientists to work out particular alleles which are present only in people with specific diseases and therefore come up with a series of DNA bases, a series of patterns, that are flags to the increasing risk of particular diseases.

Now, this information can be used in one of two ways.

Genetic testing can be done on the whole genome sequence, and those particular alleles can then be looked for and, if identified, indicate an increase in risk of developing disease.

Alternatively, genetic testing can be done using genetic probes.

So these probes are labelled with a fluorescent or a radioactive tag which can be easily detected and are put into the genome and essentially matched up with the appropriate corresponding base pair sequence.

So if the person's genome has the particular allele that increases their risk of DNA, it will be flagged up by the complementary strand of DNA attached with a fluorescent or radioactive marker joining to that allele in the patient's genome.

And you can see in the picture there how that works, where C binds to G, and A binds to T, and if the correct sequence that is being looked for is present within their genome, the gene probe will complementarily match to the allele in the patient's DNA and flag it as being present.

Now, what this means is that it indicates an increase risk of developing a disease.

It doesn't say that it's going to absolutely for certain happen, but it does indicate an increase in risk.

And this is really useful because what this means is that preventative measures can then be put in place in order to reduce the risk as far as possible in other ways.

Now, the most common form of genetic testing is done on newborn babies, and it's called the newborn blood spot test.

Now, this is a heel prick test, and, in a newborn baby, the heel is pricked, and blood is collected and tested.

And this is really useful because what it does is identify from birth any conditions that might seriously affect the baby's health or their ability to develop properly.

And what it means is that because it's been identified right early on, then appropriate measures can be put into place to help mitigate those potential issues.

Now, this test is, in the UK, recommended for all newborn babies, but it is up to the parents to decide whether or not to have that test administered because it is a choice.

It is not a compulsory thing.

It is a choice that has to be made with informed consent.

Now, obviously, the baby can't make its own informed consent.

That is delegated to the responsibility of its parents.

So let's see.

Who is correct? Izzy says, "Genetic testing can only be done on blood "using genome sequencing." Laura says, "Genetic testing can be done on blood, saliva, "or any body fluid that contains DNA." And Andeep says, "Genetic testing can use genome sequencing "and gene probes." But who is correct? I'll give you five seconds to decide.

Okay, so you should have said that both Laura and Andeep are correct.

Well done if you've spotted both of them.

So what I'd like you to consider is this scenario.

A mother has just given birth to a baby, and it is recommended that the baby has a newborn blood spot test.

The midwife says the test poses no risk to the baby, but the mother is worried.

So, firstly, who makes the decision about whether the baby has the test: the parents, the midwife, or the government? Then, can you explain what the newborn blood spot test will test for before suggesting why the results of the test could be useful? So pause the video, and come back to me when you're ready.

Okay.

Let's see how you got on.

So who makes the decision about whether the baby has the test? Well, you should have said the parents.

It is the responsibility of only the parents to decide.

Then I asked you to explain what the newborn blood spot test will test for.

And I hope that you summarise that by saying it will test the DNA from the cells of the baby's blood for the presence of particular alleles in a genome.

Make sure you're using that word allele in that sentence rather than the word gene because we're looking for variants of the gene, and a variant of the gene is an allele.

Now these alleles are associated with diseases and conditions that can affect the baby's health and development.

Then why might this be useful? Well, because it will firstly indicate the baby's risk of developing diseases, and it will also offer the opportunity for support to be provided for the baby and its parents.

This can be offered and planned for, and, if any treatments are required, these can also be planned for and started early.

So I hope you got the right idea.

Check your work over, and make sure that you have done.

And well done.

This is complex ethics and science.

Okay.

We've seen what types of genetic testing can be done.

So let's now see what these tests might be used for.

Now, genetic testing may reveal that a person has alleles associated with health conditions and diseases or allergies or adverse reactions to particular medicines.

And all of this information can be extremely useful both to the patient and also to the medical profession.

Now, the patient may well be understandably worried by the information that they receive from genetic testing.

There's a lot of data there, and it can be very tricky to interpret.

So it's really important that, when it is interpreted, it is done so expertly, and the risks are conveyed accurately and then followed up with appropriate plans for/and responses.

Now that is a form of genetic counselling provided by experts because some alleles cause disease, other alleles increase the risk of disease but do not make them certain to happen, and other alleles will provide flags to the medical profession when certain things are being considered.

So, for instance, if someone has an allergic reaction to penicillin that they hadn't discovered before genetic testing, then that would need to be considered by medical professionals from that point onwards so that it doesn't cause an adverse reaction.

Now, one of the things that this can lead to, genetic testing can lead to, is personalised medicine.

Now, personalised medicine is healthcare that is tailored to an individual's risk of ill health.

So it's not about seeing a doctor on a one-to-one basis or having the choice over a variety of different medicines, but it's about how healthcare is tailored to you as an individual based on your individual risks.

Now, this can include things like making lifestyle changes which will reduce the risk of non-communicable diseases from occurring; or choosing the correct, or most appropriate, treatments for that person; or starting treatments sooner.

And all of these are personalised responses of healthcare to an individual's risk of ill health.

Now, that information has been gained from genetic testing which includes genome sequencing, and that information can then be used by the medical profession to plan personalised medical approaches.

And this is important because what it will ultimately lead to is an improvement in the patient's life.

So which are examples of personalised medicine? a, treating a person's alleles based on genetic test results; b, planning treatments based on genetic risk factors; or c, talking to a doctor face-to-face.

I'll give you five seconds to decide.

So you should have said that planning treatments based on genetic risk factors is the example of personalised medicine, not the other two.

Well done if you spotted that.

Now we cannot currently change the alleles that we have inherited.

There's actually quite a lot of research going on about whether this is possible and how it might be done, but, at the moment, it isn't possible.

Now this means that other approaches need to be sought, but, in some ways, rather fortunately, many of the diseases that have an increased risk because of the alleles that we have inherited also are increased in risk by other factors that we can change.

So, for instance, let's consider cardiovascular disease.

Now, cardiovascular disease is the leading cause of death in the UK.

170,000 deaths per year are recorded from cardiovascular disease.

This averages out at approximately one death per every three minutes all year around.

Now, cardiovascular disease does have contributory alleles that increase risk, but there are also many other factors that increase the risk of cardiovascular disease as well including high blood pressure, high cholesterol, smoking, being overweight or obese, a lack of exercise, a diet in high fat or salt, and a family history or inherited alleles.

So we can't change the alleles that we have inherited, but what could we change from this list, and how might we go about doing that? Well, by reducing our cholesterol and the amount of fat and salt in our diet, that is likely to reduce our blood pressure.

Blood pressure can also be managed medically by taking drugs to reduce blood pressure.

Smoking and the consumption of alcohol can both be reduced if not quit entirely, and exercise can also be increased.

So it is possible to affect every single one of these factors with the exception of changing our alleles, and therefore we can actually influence our risk of cardiovascular disease by quite a significant measure.

Now, genetic testing will provide us information that can be used when we are trying to personalise our medicine, but we have to also consider not just the risk of using this information well, but the risk of using this information badly or misusing it because the genome contains an enormous amount of data about our future health.

And would you want that information to be considered and churned over by your employer or an insurance company, especially a healthcare insurance company, or a bank or a finance lender? Now, these are really important issues to consider because these contextualise the decisions that we are making about our health because although it is possible to have genetic testing done, we need to consider the ramifications, the issues that that might pose as well.

So, in most countries, including within the UK, the use of genetic testing is heavily controlled by the law and by overseeing bodies who manage those processes.

But it is still nevertheless a potential source of risk.

Just like having a phone, and having that being able to be hacked in one way, shape or form, this data has risk associated with it in other ways other than just our health management.

So who is correct in this scenario? Aisha says, "Genetic testing helps us understand our risk "of some diseases." Alex says, "Genetic testing is a process "that prevents diseases," and Lucas says, "Genetic testing is regulated "to reduce the risk of misuse of results." Who is correct though? I'll give you five seconds to decide.

So you should have said that Aisha and Lucas are both correct.

Well done if you spotted both of them.

So what I'd like you to do now is to firstly suggest why genetic testing is an example of gene technology that can help to improve our lives.

Then I'd like you to consider this scenario.

Now, Izzy's father has had a genetic test, and he's worried because the results show that his genome contains alleles which increase the risk of cardiovascular disease.

So what I would like you to do is to write some helpful advice to Izzy's father, things that he can do that might help him to reduce his risk in other ways.

Then I would like you to consider that various companies now offer genetic test kits that can be used at home, or direct-to-consumer genetic testing it's also called, and the results are provided to the patient either in a text message or by logging onto a webpage.

Now, in recent years, the UK government has debated laws about regulating these tests.

So what I would like you to do is to suggest why the following regulation could be helpful.

So why would requiring companies to provide access to genetic counselling be helpful? And why would laws to control confidentiality of results be necessary? So pause the video whilst you consider all of those three scenarios, and come back to me when you're ready.

Okay.

Let's check our work.

So, firstly, I asked you to suggest why genetic testing is an example of gene technology that can help to improve our lives.

So you might have included that genetic testing, which includes genome sequencing, can show whether a person's genome contains alleles that increase the risk of ill health.

And what this is useful for is to make decisions and to inform future actions.

For instance, people can make lifestyle changes to reduce the risk of disease, and doctors can choose the correct treatments, and those treatments can all be started sooner before the disease even shows itself as symptoms. Then I asked you to write some helpful advice to Izzy's father who has discovered that he has an increased risk of cardiovascular disease.

So hopefully you've included the fact that the alleles in the genome increase the risk of cardiovascular disease, but they do not necessarily make it certain to happen, and that the risk of cardiovascular disease is also affected by many other risk factors that can be changed to reduce the risk.

So, for instance, Izzy's father could stop smoking.

He could reduce the amount of fat and salt in his diet.

He could get more exercise.

And these are three simple things that he could do to significantly reduce the risk of cardiovascular disease.

And by making these lifestyle changes, what it will do is reduce obesity, high blood pressure, and high cholesterol, and these are also risk factors for cardiovascular disease.

So by doing these three minor changes, you impact on three other significant risk factors and therefore can actually significantly reduce the risk of cardiovascular disease from perhaps up to six different vantage points.

Then I asked you to consider why regulation of various different factors could be helpful.

So, firstly, why requiring companies to provide access to genetic counselling? So the results of genetic testing may well be very worrying for patients, and it's certainly very confusing and complicated data that requires expert handling.

It's important to interpret those results properly, assess the risk correctly, and plan appropriate responses.

And these are all processes that must be done by someone who is expert in that field.

So requiring companies to provide access to genetic counselling will provide those patients with access to expert assistance.

And how would laws to control confidentiality of results be helpful? Well, it's very important to reduce the risk of genetic testing results being misused by groups such as employers, insurance companies, and finance lenders.

Now, all of these groups would find that information perhaps very useful to them when they're assessing risks to their own business but could use that information in ways that do not benefit the patient and could also use them without consent.

So laws controlling the confidentiality of results would be very important to prevent that happening.

Also, it must be important to make sure that patients are not forced to take a test because an employer or an insurance company or a finance lender requires it.

This is something that must be chosen by the patient only under an informed consent scenario rather than being pushed into it because of a decision by a company.

So I hope you've got all of those ideas written down and can add to your notes where you have some other things that you might include.

Well done.

This is really tricky, ethical, and genetic science.

It's certainly a real minefield, and so well done for trying this.

Okay, we've reached the end of our lesson today now, and it is very difficult science and ethics here and how the two fuse and overlap with each other.

But in our lesson today, we have seen how some alleles, that's versions of genes, affect health, for instance, by increasing the risk of non-communicable diseases or adverse reactions to treatments.

Now genetic testing and genetic sequencing can identify the presence of these alleles within a person's genome, and these results can then inform personalised medicine and lifestyle changes that can decrease risk and improve health.

But genetic test data can be misused, and that is why it must, and is, regulated.

So I hope you found that really interesting.

So thank you for joining me today, and I hope to see you again soon.

Bye.