Common Mutations We Inherit from Our Parents

5 minute read

By Jordana Weiss

When you’re a student in high school, you probably did a few projects on genetic mutations, and the ways that our parents’ biology and genetic makeup influences our life. With an online search, you can learn more about genetic mutations.

Germ-line mutations are inherited from our parents, and they help decide a lot of things about us before we’re born. There are some mutations that are negative, while others can have a positive or neutral impact on our lives.

1. Blue Eyes

It seems unbelievable, but scientists have tracked down the source of the mutation which causes blue eyes. It seems that the mutation came from one single person who lived over 6,000 years ago! Research shows that this person is the ancestor of every single person alive on Earth who has blue eyes.

Originally, every person on Earth had brown eyes, but eventually a chromosomal switch in this one person created the option for blue eyes. After that, whoever he or she had children with carried this gene for blue eyes, passing it down through history. This research took over 10 years to complete, and surveyed people with blue eyes all over the globe.

2. Color Blindness

Color blindness, which generally affects a much higher percentage of men than women, can be acquired through an illness or medical condition, but is most frequently inherited from our parents.

The condition is carried in the X chromosome, which explains why men are affected at a much greater rate than women. Women can be carriers of the genetic mutation for color blindness, but generally will not see any effects from the mutation in her own vision — she’ll only pass it down to her children. Color blindness affects roughly 8% of men worldwide.

3. Dimples

You may think that dimples occur randomly, but in fact they are most frequently a genetic mutation that requires one or both parents to carry the gene in order for the phenomenon to occur.

If both parents carry the gene, then there is a 50-100% likelihood that their child will have dimples. If only one parent carries the gene, then their child still has a 50% chance of having dimples.

4. Tongue Folding

This mutation is a fun one to test for as many children find it confusing that they are simply unable to roll their tongue, while their friends can do it with ease.

Although it is possible to teach yourself the trick if you try hard enough, scientists have debunked existing studies that claimed that this was a genetic trait. Now, scientists believe that while genetics do play a role, other factors from our upbringing influence this ability as well.

5. Left-handedness

In the past, scientists believed that one single gene determined whether we were left handed or right handed at birth. Now, it is thought that up to 40 different genes contribute to this phenomenon.

No one single gene of these 40 are able to determine whether a person dominantly uses their left hand, but together they determine a preference that lasts for a person’s entire life. Left-handedness used to be seen as a malevolent sign, but now it’s just considered a slightly rare, yet normal, personality trait. Ambidextrousness — using both hands interchangeably — is rarer still.

6. Red hair

Red haired folks among us are often singled out because of their rare and beautiful genetic mutation. This mutation is commonly used as an example in schools when teachers try and explain genetics because it’s a classic example of a recessive gene.

The gene that determines whether we or our children will have red hair is called MC1R. Depending on which combination of the gene we get from each parent, and whether that gene is recessive or dominant, we can determine whether our children will have red hair or not.

7. Cleft Chin

Cleft chins, long the staple of Hollywood’s most dapper leading men, are widely considered to be genetic mutations. However, modern research has shown that like left handedness, there are more factors to be considered when determining whether this is a trait that is solely determined by one’s genetic makeup.

There are many varieties of cleft chin, ranging from very obvious to almost undetectable, and although inherited genetics do play a factor, it is possible for completely spontaneous genetic mutations to occur as well.

8. Baldness

Bad news for those among us that are prematurely balding – it looks like no matter how many specialty shampoos or organic homeopathic cures you try, balding is 80% determined by genetics, so there’s not a whole lot you can do to change your situation.

Even though there have been plenty of studies done, the closest scientists have been able to come to determining which gene causes baldness is to isolate a small region of our chromosomes, which they believe is the general site of the offending mutation.

9. Phenylketonuria

Phenylketonuria, commonly known as PKU, is a genetic disorder that we inherit from our parents that causes a build up of phenylalanine in our bloodstream. This protein build-up can cause major health problems if left untreated.

Babies with PKU start exhibiting symptoms such as a strange musky odor or pale skin soon after birth, and if left untreated even for a few months, the protein build-up will cause irreversible brain damage. Mothers and fathers can pass this down to their children if both of them carry a mutated gene, even if they never show symptoms of the disorder themselves.

10. Super Immunity

This genetic mutation is extremely rare, affecting only three people in recorded history. However, we wanted to touch on it today since the research on this mutation could lead to untold discovers in the field of medicine.

The only two people with this immunity who are still alive are a brother and sister, who are both currently immune to many serious viruses like herpes, dengue fever, and HIV. Their bodies are unable to attach sugars to proteins, which is a basic process that most human bodies require. As a result, viruses are unable to multiply in their bodies, but the regular processes of life are inhibited as well, leaving these children severely developmentally delayed.

11. Cystic Fibrosis

This disease, if left untreated, can cause people to feel like they’re breathing through a straw, unable to get the proper amount of air into their lungs. Cystic Fibrosis (CF) causes a build-up of mucus in vital organs like the pancreas and lungs, which causes both digestive issues and eventually respiratory failure.

This disease is caused by a genetic mutation carried by both parents. For every child that is born to parents who are both carriers of the mutation, there is a 25% chance that the child will have CF, and a 25% chance that the disease will skip over them entirely.

12. Down Syndrome

This genetic mutation is caused by a single chromosome accidentally repeating itself. If a child is born with a duplicate or even partially duplicated chromosome 21, then they will be born with Down Syndrome.

Down Syndrome is the most common chromosomal condition in the United States, with one out of every 700 babies born carrying the mutation. While researchers are actively working on discovering the cause of the mutation, the only factor that they have been able to isolate is maternal age. The older the mother is, the higher chance she has of bearing a child with Down Syndrome.

13. Huntington’s Disease

Huntington’s disease is a horrific genetic condition that affects a person’s basal ganglia region of the brain, leading to a breakdown of nerve cells which render a person unable to walk, reason, or speak.

It usually begins affecting people at around 30-50 years old, and will progress over the next 10-30 years until the person succumbs to complications from the disease. The genetic mutation that causes Huntington’s disease is carried in a single gene, which means only one of your parents needs to have it for you to have a 50% chance of developing the disease yourself.

Jordana Weiss