Genetics Training

Epigenetics and genetics

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Epigenetics and genetics

Chapter 18
Genetic counseling training

Training video

Through genetic counseling, learn what epigenetics is, how it will affect the genetics and epigenetics, and how useful it can be

Spoken text of the video

Chapter 18
Epigenetics and genetics

Epigenetics is a well-known, forever expectant effect, which goes hand in hand with genetics, but also presented relatively appealing in the media since it can be influenced by the lifestyle, while gene defects are inherited and cannot be changed.

I want to briefly explain the concept (of) epigenetics and show how it, together with genetics, plays a role, because there are some people who say only epigenetics matters, genetics is the old hat, epigenetics is the future. Others say that epigenetics is exaggerated and only in genetics lies the real information, and still others are somewhere in between.

My own background: I'm (really) epigeneticists and during my PhDs studies I often switched on and off between genes and epigenetics. That is, epigenetics is a kind of light switch for genes, through which one can actually regulate genes, i.e. turn them "silent" or "loud". In other words, I am familiar with epigenetics and I would like to briefly explain what epigenetics is and how it interacts with genetics.

Genetics is the blueprint of the body. That is, the genes contain the blueprints for proteins and processes in the body. So genes contain information about how the body should be built.

For example:

  • How is the food digested?
  • How is the blood sugar regulated?
  • What color should the eyes have?
  • How are the strong bones built?

A genetic defect that interferes with these genes is leading to a lack of function of the body and can thus trigger diseases.

On the other hand, epigenetics is a sort of "volume control" for genes. This is based on the principle that environmental factors can switch the genes, turn them "silent" or "loud". This "louder" or "quieter" genes influence the various processes in the body. And what is also interesting: the epigenetic programming can be inherited, that is, the "louder" or "quieter" settings which are formed in one person can be passed on to the offspring. This means that the environment influences a person and that person passes this environmental programming to their children. And that's the interesting thing about epigenetics.

This was first scientifically proven in 1944 in a study conducted in the Netherlands. There was famine in the Netherlands during the postwar period. Women who were pregnant at this time could eat only 400 kcal per day. The children were still born healthy and the supply of food improved gradually. This means that the famine affected only the pregnant woman, but not their child. This child grew up, always had enough to eat and was later pregnant. Then it was determined that this group of people, who were in the belly of their mothers at the time of famine, have an increased likelihood to suffer from heart diseases, breast cancer or overweight. The medical records allow keeping track of the family history.

This is easy to understand considering that the fetus has developed only with a few nutrients. It is understandable that the body might have some weaknesses, as it has developed under these circumstances. But here's the really interesting thing: these ladies also got pregnant and had children, who have grown up with enough food. Just like their parents, the adults of 2013, 2014, 2015 have an increased risk for heart disease, breast cancer and obesity, although the cause can be traced back two generations ago.

What is obvious here is that a circumstance occurring during the life of the grandparents has passed on to the following generations and triggers medical problems. There is no defect - the genes themselves are fine - but it's actually the lifestyle factor which has led to this.

Let's briefly look on how epigenetics works:

Here we have a gene for digesting lactose. In other words, the task of this gene is a blueprint for the enzyme that can digest lactose. And now comes the epigenetics: there is something that is called heterochromatin. One can imagine it as a wrapping for the gene. This means that the gene is the DNA strand and there we have molecules which close this gene and thereby firmly turn it "quieter". The information carried by this gene is turned "quieter" and the production of the enzyme for lactose is in this case reduced or switched off completely.

This begs the question: how can this work with inheritance?

Let's imagine the following situation: we have a woman whose genes are all normally regulated. This woman has a daughter - here are also all the genes normally regulated. Each of these genes has a specific function. Now the daughter suffers a famine and certain genes are adjusted by epigenetics. That is, some genes are turned "quieter", thus influencing their functions. This programming will remain in this person and is the daughter, so the granddaughter of the first woman, who inherits and passes them further. That is, this programming can be inherited and it is not a defect, but rather a lifestyle factor that has influenced entire generations (and will continue to influence).

Now the question arises: if epigenetics turns the genes on and off, can it also overcome the effect of genetic defects?

Let's look at an example:

This gene causes the body to digest lactose. Now we are building a genetic variation and destroy this gene. That is, the body loses completely the function of this gene, cannot digest lactose, and lactose intolerance is triggered. A genetic variation, i.e. genetic modification, has caused this. Here it is now relatively unimportant whether epigenetics turns this gene "quieter" or "louder", because this gene is completely destroyed and has no effect anymore.

That is, the answer is: some genes destroy the instructions for the body. These are then completely lost and cannot be rescued by epigenetics.

An example:

Gene mutations that cause severe diseases.

I have to say: it is certainly the case that certain lifestyle circumstances adapt our epigenetics. We still know relatively little about it. We know that a healthy diet can have epigenetic benefits on health, that the body is simply programmed to "healthier" and that this program upholds. But epigenetics is still very difficult to measure, particularly since it may occur differently in various tissues. That is, one can measure only if one takes out a tissue sample, which is naturally not possible in some tissues. And we do not know how to change a badly programmed epigenetics. Let alone, how the negative epigenetics can be seen.

That is, there are no doubt epigenetic features that can also modify disease risks. We still know very little about how we can measure it and how it affects us. There will certainly be more in the future epigenetic studies, and more insights. Perhaps someday we can actually find something useful, in the sense that we can say: if these genes are quieter -regulated, then we can turn them back louder with a certain lifestyle change, and that in turn would result in a lower disease risk. Such a thing would be usable information.

That will surely happen someday, but we are not there yet. But we do know genetics. As I said before, genetics outdo epigenetics in many cases.

Of course, we will keep an eye on the latest research results and integrate them into programs, to the extent this makes scientific sense.

At the moment we are focusing on genetics, which allows us to find lots of information relevant for our health. And until epigenetics further evolves as a field and provides us with additional information, we remain at the genetics, which is already giving us plenty of information.

And this is the end of Chapter 18 "Epigenetics and genetics".

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