In very rare circumstances, errors with a person's genetic code can result in some very interesting physical abnormalities. Here we have gathered some of the most interesting, and sometimes disturbing, examples of genetic physical conditions from around the world.
Before you read on please note that some of these images are a little distressing. You have been warned!
What are some of the rarest genetic physical disorders?
So, without further ado, here are some of the rarest genetic physical disorders from around the world. This list is far from exhaustive and is in no particular order.
1. This man was actually born with two middle fingers on each hand
While it may look like this photo has been photoshopped, it is actually a strange quirk of genetics. The condition, called polydactyly ("many fingers") is actually hereditary.
For this reason, his son has also inherited the trait and has 12 fingers and toes. Unlike his father, these extra digits were removed via surgery when he was very young.
Also known as hyperdactyly, it can be seen in various other animal species as well as human beings -- though it is pretty rare.
2. This rare genetic condition is called "mirror hand syndrome"
Here is another interesting rare genetic condition that can affect people. Again it may be hard to believe that such a condition can actually exist, it really does.
Called, ulnar dimelia, this strange genetic disorder results in the person's ulna being duplicated, and no thumbs are developed. This often results in the person having seven or eight fingers in a single hand.
The condition is also known as "mirror hand syndrome" for obvious reasons.
3. Here is another interesting finger-related genetic condition
As we have already seen human hands and fingers can be quite susceptible to genetic conditions that result in very strange developments. In this case, this condition actually results in having fewer fingers than is "normal".
In this image, the person only has four fingers in their hand and an index finger where their thumb should be. This genetic condition is called symbrachydactyly which leads to babies being born with underdeveloped or abnormally formed fingers.
The condition is usually treated using surgery and/or prosthetics.
4. This fellow was born with two symmetrical hair crowns
Here is yet another interesting genetic condition in humans. In this case, this person was born with not one, but two crowns or whorls on their head.
In this case, the multiple crowns grow in opposite directions enabling him to grow a natural Mohawk with ease. Every cloud has a silver lining, as they say.
5. This person has tentacles under their tongue
Again this image is not photoshopped. This person really does tentacle-like structures dangling underneath her tongue.
Such elongated structures are called plica fimbriata and are, thankfully, completely harmless. They can, however, get stuck between your teeth on occasion.
6. This chap has an amazing ability to grab things backward
You might have to take a closer look at this image to figure out what is going on here. As you can see, they can actually extend their fingers backward so much that they are able to actually grab and hold things in reverse.
The condition, called hypermobility, is usually more common in young children. Any parent will distinctly remember how flexible their little bundles of joy are as babies.
This ability is usually lost with age and is only seen in about 5% of adults.
7. This chap was actually born without a bridge inside their nose
Amazingly, this person was actually born lacking most of the cartilage inside their nose. This enables them to compress it with ease.
Technically known as absent nasal cartilage, it is not really understood how this condition occurs.
Apparently they also never suffer from nose bleeds! Could this be the next step in our evolution? Most probably not.
8. This person has a not so small "little finger"
In this interesting genetic condition, this person's pinky finger just so happens to be the largest finger on their hand. This monster-little-finger certainly would be useful in some situations.
Technically called macrodactyly, this genetic condition causes certain fingers to grow abnormally large. It can also affect the entire hand and forearm on some occasions.
It is very rare and usually affects the index finger, though not always as in this case. It is usually treated using surgery and amputation is usually recommended.
9. This genetic condition prevents patients from bending one or more of their fingers and thumbs
While you might not be able to realize the problem from this image, this person was born with a condition whereby they are unable to bend one of their thumbs.
The condition, known as "trigger finger", is caused by the tendons that normally allow the thumb to bend being constantly swollen and locked. Technically called stenosing tenosynovitis, it usually affects either the thumb or the ring finger.
Apparently it affects somewhere in the region of 3.3 children in every 1,000.
10. This poor baby actually has two faces
In this distressing image, this baby has actually been born with not one, but two faces. This genetic condition is called diprosopus, and it is incredibly rare.
Also known as cranial duplication, this causes parts or all of the face to be duplicated during development in the womb. It is caused by abnormal activity in the protein SHH (sonic hedgehog).
This genetic condition can also be seen in various other animal species'.
11. This person actually managed to grow a horn on their head
As you can see from this image, this person has actually grown a real-life horn on their head. The disorder called cornu cutaneum, this horn is actually an abnormally large skin tumor.
This disorder is very rare and any horns that form are usually very small. However, in some unusual cases, especially if left untreated, these horns can grow quite large indeed.
For example, one French lady called Madame Dimanche managed to grow a horn that was in excess of 10 inches (25.4 cm).
12. Human cyclops is actually a real thing
In this distressing image, you can actually see a real-life human cyclops. This is another incredibly rare genetic disorder and is characterized by human embryos failing to develop properly.
The disorder, called cyclopia (for obvious reasons) is the result of an embryo failing to divide the track of the eye into two hollows. Interestingly, while rare in humans it can be more common in animals.
13. This person's foot grew backward for some reason
When this woman, called Wang Fang, was born it was feared she wouldn't be able to walk properly as an adult. But, as it turns out, she learned to walk perfectly fine.