Have you heard of DNA mutations? Let's learn about Somatic & Germline Mutations in a simple way!

Have you ever wondered how some diseases in our body are passed down from generation to generation , or how some diseases suddenly appear? One reason for this is the small changes that occur in our genes, that is, DNA mutations ( mutations ). Today we will talk about this very simply, in a way that you can understand.

What are DNA mutations? Let's understand it simply!

Simply put, a DNA mutation is a change in your DNA sequence, that is, your genetic information. Think of it like a recipe for making a dish. If a letter or word in this recipe is slightly changed, the taste of the dish can change, right? That's what a DNA mutation is like. These changes in DNA, that is, mutations, often occur when our cells divide and new cells are formed. But don't worry, most of the time these changes in DNA do not have a major impact on our genetic makeup, and they do not cause any disease. However, there are some mutations that can cause genetic conditions that affect our health. There are thousands of such genetic mutations that can occur when our cells divide and new cells are formed. Among them, there are two main types:

• Germline mutations
• Somatic mutations

Now let's look at these two types separately.

There are two types of mutations: germline and somatic.

What are Germline Mutations?

Germline mutations are mutations that occur in the reproductive cells of the parents, either the egg cells or the sperm cells. These mutations change the genetic material that the child receives from the parents. Simply put, these are hereditary mutations. You can inherit these germline mutations from either your mother or your father.

Imagine that there is a slight difference, a mutation, in one of the mother's or father's egg cells or sperm cells. Then, when those cells come together to form a child, that mutation is passed on to the child. That's why these are called hereditary mutations.

What are Somatic Mutations?

Somatic mutations are changes in the DNA of any cell in a person's body that is not a reproductive cell (egg or sperm) after conception. Importantly, these somatic mutations are not passed from parents to children (not hereditary). They can occur randomly, meaning they can occur suddenly, without any family history. Also, they are not passed on to future generations. Simply put, if a change in the DNA of a cell in your skin or lung after you are born, such as a cell in your lungs, that is a somatic mutation. It is not passed on to your children.

How do these mutations affect our bodies?

As we mentioned earlier, most mutations do not cause us any problems. However, some mutations can cause symptoms. Genetic conditions are disorders that are caused by changes in our genome. Your genome is the complete set of genetic information made up of your DNA, genes, and chromosomes.

Can a mutation be passed from generation to generation?

This is a very important question.

• Germline genetic mutations can be inherited because the mutation occurs in the reproductive cells (eggs or sperm). Since eggs and sperm are passed from parents to children, the mutation is also inherited.
• You cannot inherit somatic mutations because they occur randomly in cells that are not eggs or sperm.

Where is our DNA? What does it look like?

DNA is found in every cell in our body (there are trillions of cells in our body!). It contains our genetic code. This genetic code is like the instruction manual for how our body works. As for the shape of DNA, it is a structure made up of four bases:

• Adenine (A)
• Cytosine (C)
• Thymine (T)
• Guanine (Guanine - G)

These bases are paired together in pairs: A with T, C with G. These base pairs, together with a sugar molecule and a phosphate molecule, form nucleotides. When these nucleotides are joined together, they form a spiral staircase inside our cells, a double helix. In this case, the base pairs are like the stairs of the staircase, and the sugar and phosphate molecules are like the handrails of the staircase. Isn't it an amazing design?

How and where do germline mutations occur?

Germline mutations cause changes in the DNA of reproductive cells. When an egg and sperm join during fertilization, those cells divide to make new cells, creating an embryo. Parents who are carriers of a mutation can pass the mutation on to their children.

How and where do somatic mutations occur?

A somatic mutation is a change in a person's DNA that occurs after fertilization, in any cell in their body that is not a sperm or egg (germ cells). Human cells are constantly dividing and being replaced by new cells. If a mutation occurs, all other cells that develop from that affected cell will have that mutation in their DNA.

What are the common conditions caused by germline mutations?

Inherited conditions are caused by germline mutations. There are hundreds of such conditions, but some of the most common germline mutation-related conditions are:

• Sickle cell disease
• Cystic fibrosis
• Tay- Sachs disease
• Huntington 's disease

What are the common diseases caused by somatic mutations?

Somatic mutations can also cause diseases that affect a person's health. Some of the common diseases caused by somatic mutations are:

• Skin cancer
• Lung cancer
• McCune-Albright syndrome
• Sturge-Weber syndrome

Are there tests to detect these mutations?

Yes, genetic tests can detect these mutations, that is, changes in your genes, chromosomes, or proteins. Genetic testing can find out exactly which gene or chromosome has the mutation. If there is a family history of genetic conditions in the parents, these genetic tests can help understand the risk of having a child with a genetic condition.

How do we protect ourselves from these mutations?

This too needs to be discussed in two parts.

Things that can minimize somatic mutations:

Fortunately, there are some things we can do to reduce the risk of somatic mutations:

• Using sunscreen when in the sun and reducing exposure to UV rays.
• Using personal protective equipment, such as a protective mask and gloves, when working with chemicals.
• Not smoking.
• Eating a healthy diet and exercising.

Let's be aware of Germline Mutations:

We can't prevent inherited germline mutations. However, you can talk to your doctor about genetic testing to understand your risk of having a child with a germline mutation. This is especially important if you have a family history of genetic conditions.

Remember the most important thing! (Take-Home Message)

From what we've talked about today, you may have understood that changes in our DNA, or mutations, are not something to be afraid of.

Most of the time, changes in DNA do not cause genetic conditions. However, some DNA changes can affect your health.

• If you have a family history of genetic conditions, talk to your doctor about genetic testing to understand your risk of having a child with a germline mutation.
• Try to avoid somatic mutations as much as possible, which are not inherited. To do this, protect yourself from the sun, avoid harmful chemicals, and maintain a healthy lifestyle.

I hope this information is helpful to you. If you have any questions, never hesitate to ask a doctor.