8 Rarest Body Features That Exist In Humans

Having two different color eyes

People often debate whether their eye color is rare or not. For example, blue eyes are pretty rare, and green eyes are even rarer. But nothing beats the rarity of having two eyes of completely different colors!

Possessing two different eye colors is known as heterochromia. Heterochromia can be caused by certain medical syndromes or even injury to the eyes. But on rare occasions, people with chimerism (or an extra set of DNA absorbed in the womb), can have different eye color genes in each eye that cause heterochromia.

Those with two different colored eyes are some of the most striking people in the world. But we can only imagine the trouble they have listing their eye color on a driver’s license!

Unbreakable bones

What if having a seemingly superhuman ability wasn’t everything it was cracked up to be? This is what a few people have discovered over the years after they were diagnosed with unbreakable bones.

No, that’s not a typo. A small handful of people experience a mutation in their LRP5 gene. This mutation causes them to have very dense bones. In one documented case, a gentleman had bone density eight times greater than those of a normal person, and this allowed him to literally walk away from a car accident that should have shattered most of the bones in his body.

Having unbreakable bones sounds like a superpower (just ask Bruce Willis, star of the 2000 movie Unbreakable). However, those with such heavy bones struggle with everything from an afternoon swim to getting a hip replacement.

Excessive hair growth, or “werewolf syndrome”

Some people are hairier than others. This includes growing more hair on top of their head, on their chest, under their arms, and so on. But what if you had uncontrollable hair growth all over your entire body?

This happens to those who have the condition hypertrichosis, also known as werewolf syndrome. The condition varies, though, with people growing excessive hair in either specific places or all over their body.

Where some forms of hypertrichosis can develop later in life for reasons such as malnutrition or cancer, congenital hypertrichosis terminalis is a genetic disorder where people grow unusually thick, long hair on their face and body since birth.

Some of the known cases of this date back to the 19th century, when people with this condition found work in traveling circuses throughout the country.

Hair that can’t be combed

It’s tough to beat a condition where hair grows uncontrollably over your body. However, some people suffer from a hair condition almost as annoying as that. And this condition keeps their hair from being combed!

While many conditions have complex names, this one is very on the nose. “Uncombable hair syndrome” (sometimes called “spun glass hair”) refers to a condition where dry, frizzy hair grows out of the scalp. To make things stranger, this hair is often silver or bright blond and (as the syndrome name implies) cannot be combed.

This condition is so rare, only about 100 people have been diagnosed with this syndrome.

Having no fingernails or toenails

There are plenty of health warning signs that you can find in your nails. However, some people can’t benefit from these warning signs for a simple reason. They have no nails on their fingers or toes.

This rare condition is known as anonychia congenita. Those with this condition have mutated genes that cause their bodies not to produce the protein necessary for growing fingernails and toenails.

Fortunately, this condition is very obvious, and those who suffer from it can easily ask their doctors about how a lack of fingernails and toenails will affect their lives.

A heart located on the right side of one’s chest

For about 99% of the population, the heart is on the left side of the chest. For the remaining 1%, though, their hearts are actually on the other side!

The condition is known as dextrocardia. To make things spookier, doctors haven’t determined exactly what causes it. But it’s important to get diagnosed early. Some of those who have this condition suffer from things like immune system problems and difficulty breathing.

In some extreme cases, this condition causes enough problems that surgical intervention is necessary. For others, this condition may amount to little more than an occasional annoyance.

Black people born with blue eyes

We tend to make a lot of assumptions about other people. For example, many assume that Black people cannot have blue eyes. However, that assumption is dead wrong.

In reality, many Black people around the world have a mutation in their OCA2 gene. This is the gene that produces the melanin that, among other things, determines what somebody’s eye color is.

The default genetic eye color for pretty much everyone is brown, but OCA2 gene mutation leads to many different colors. And this includes giving Black people around the globe very striking sets of blue eyes!

Black people with naturally blond hair

Previously, we touched on the assumption many people make that Black people are not born with blue eyes. A related assumption is that Black people are not born with blonde hair. And just like the earlier assumption, this couldn’t be further from the truth.

In the Pacific islands of Melanesia, up to 10% of the native Black population is born with naturally-blonde hair. This is due to a DNA mutation that has given these residents the TYRP1 gene. This gene produces blonde hair and is typically limited to Caucasians.

It just goes to show that whatever assumptions you make about the world, there are places in the world ready and willing to prove you wrong!