A genetic mutation is an alteration in the DNA sequence that makes up a gene, meaning the sequence differs from that found in most people. In other words, a gene's information inherited from the person's parents may act differently from how it was intended to. Imagine swapping letters in words in a sentence — this may render the sentence no longer intelligible or give it an entirely different meaning.
These sorts of mutations are actually fairly common; they are how species evolve. However, mutations can't really be called "normal", as they happen completely at random. For example, a mutation could occur if a cell doesn't split correctly in the early stages of a fetus's life. Environmental influences are also a factor. While some mutations are inheritable, others may only affect your own body and can have quite drastic consequences, such as increasing the risk of cancer. Of course, not all genetic mutations have negative outcomes, and some can even have their advantages! So here are 8 of the most common genetic mutations — do you have one of these?
1. Red Hair
In the olden days, red-headed women were considered to be witches, as this hair color was so rare. Today, it's estimated that 2-6% of Americans have read hair. In Ireland, this figure is around 10%. Ginger hair is caused by a gene responsible for the pigment eumelanin being inactive. Since eumelanin gives hair a dark color, this gene's inactivity results in a different pigment becoming dominant, meaning the person will have blonde or ginger hair instead.
2. Lactose Intolerance
Only very few Europeans have an intolerance to milk. However, people from East Asia are more likely to suffer from lactose intolerance. Contrary to popular belief, lactose intolerance isn't actually a genetic mutation — the opposite is in fact true. That's because Mother Nature only intended milk to be a means of feeding babies. As we get older, our ability to digest milk and milk-based products worsens. The only exceptions are people with a European background. It's assumed that a random genetic error between the Stone Age and beginnings of rearing cattle led to people using animal's milk as an additional source of protein.
3. Reddening from Alcohol
Some people's cheeks turn red when they drink alcohol. This is caused by a mutation to the ALDH2 gene, resulting in the blood vessels in the person's face to widen and leave their cheeks appearing red. While a red face after drinking a glass of wine is usually harmless, it may also point to an "alcohol flush reaction," i.e. alcohol intolerance. In this instance, the body needs considerably more time to break down the toxic agents in alcohol. Over time, this could lead to health problems. If you have headaches or sickness even after consuming small amounts of alcohol, you should consult a doctor.
4. Blue Eyes
From Elton John to Lou Reed, many musicians have sung about this popular eye color over the years. However, few people know that blue eyes were actually the result of a genetic mutation from 6,000 to 10,000 years ago. Before then, it's assumed that everyone in the world had brown eyes. People have blue eyes when the gene responsible for the pigment melanin is inactive. This is also true for green-eyed and gray-eyed people, though they only have lower amounts of melanin. Since melanin is a natural sun filter, people from northern countries are more likely to have light-colored eyes. They are all probably descended from one person who had this random genetic mutation.
5. Red-green Color Blindness
Is the apple red or green? This is a tricky question for people who have red-green color blindness. Due to insufficiently developed or missing cone cells in their retina, those affected cannot distinguish between the two colors or have real trouble doing so. Thankfully, most items are labeled on the fruit and veg stand.
6. Short Sleeper Gene
Do you have no trouble going to bed late and then getting up early? Well, you probably have the short sleeper gene! People with this gene only need three to fours of sleep to feel fine the next day. That means you have four extra hours a day on your average person without this genetic abnormality. Not bad, eh?
7. Anti-malaria Gene
Though no longer a major health issue in Europe, malaria continues to cost many people's lives in tropical and sub-tropical regions. However, this does not affect people with the anti-malaria gene in these areas. Unfortunately, this is no reason for joy, as these people also suffer from sickle-cell disease, an inherited illness that causes the red blood cells to lose their elasticity. This can lead to red blood cells becoming stuck in blood vessels and causing them to burst.
8. Missing Wisdom Teeth
Increasingly fewer people have wisdom teeth. These teeth are from a time when people had wider jaws. The oldest skeleton found without wisdom teeth is 350,000 years old, which shows that this genetic mutation has been around for a while. It's assumed that the development started in China, as this is where most people don't have wisdom teeth. But does that mean wisdom teeth will all but disappear within the next few centuries? Not quite — it would take quite an impressive genetic mutation for that to happen.
So do you or anyone you know have any of the genetic mutations listed above? It's most likely that you do. As we've said before, genetic mutations are more common than you might think — and any you do have are part of the combination that makes you uniquely you.