Let's get right into it. Number nine, two people in one body. Your body could contain two different sets of DNA. This rare condition is called chimeism. It happens when you absorb your twin in the womb. Your twin vanishes, but their DNA lives on inside you. Different parts of your body can have completely different DNA. Your skin cells could have your DNA while your blood cells could have your twins. The craziest part is most people with chimeism have no idea they have it. But sometimes there are visible signs like two different colored eyes or patches of skin with different colors or textures. Some chimeas even have two different blood types flowing through their veins. One woman almost lost custody of her kids because of chimeism. A DNA test showed she wasn't the mother even though she gave birth to them. Turns out the reproductive cells that made her kids had her twins DNA, not hers. Another case is model Taylor Mull, who has a perfectly straight line down her torso. One side is a different color than the other. A visible dividing line shows where her DNA changes. Chimeism is probably way more common than we think. You could be a chimera right now and never know it without specific genetic tests. Number eight, permanently uncombable hair. Imagine waking up every day with hair that looks like you stuck your finger in an electrical socket. That's the reality for people with uncomable hair syndrome. This isn't just a bad hair day. It's a genetic condition where your hair literally cannot be combed flat. It's so rare that only about 100 cases have ever been documented worldwide. The hair grows out in all directions like a mad scientist, refusing to lie flat. It's usually silvery blonde or straw colored, giving kids this weird Einstein look. Scientists figured out it's caused by mutations in three genes: TCHH, P AI3, and TGM3. These genes are the construction crew for your hair. When they mess up, you get hair shafts that are triangular instead of round. Normal hair is shaped like tiny cylinders, which is why it can lie flat. But with this syndrome, each strand is like a tiny three-sided prism that physically cannot lie flat against the others. The condition usually shows up when kids are super young, sometimes as early as 3 months old. The good news is that for many people, the condition actually improves during puberty. It's like their body finally figures out how to make normal hair after years of practice. Besides the unique look, the condition is completely harmless. Number seven, blood of gold. Imagine having blood so rare that only about 50 people on the entire planet share your type. It's called RH null blood or golden blood. People with this blood type are missing all the Rh proteins on their red blood cells. Most people have these markers, but people with golden blood don't. This blood type was first discovered in 1961, testing an Australian woman's blood. Scientists initially thought having no RH proteins would be fatal, but these golden-blooded people can live normal lives, although with major complications. Their blood is like liquid gold for medicine. People with Rhn null blood can donate to anyone with rare blood types in the Rh system. But if they need blood themselves, they're in serious trouble. Their body will violently reject any blood that has even one Rh antigen. They can only receive blood from another person with Rh null. There are only about nine active blood donors with this type in the entire world. Nine people. If someone with golden blood needs a transfusion, finding a match is like looking for a needle in a global haystack. This means people with golden blood often avoid dangerous activities like motorcycle riding. A serious accident could require a transfusion that might be impossible to get in time. Number six, mismatched peepers. Heterocchromia is when someone has two different colored eyes. It's a rare condition affecting less than 1% of the world's population. There are three types. Complete heterocchromia is when each eye is a totally different color, like one blue eye and one brown eye. Segmental heterocchromia is when parts of the same eye are different colors. And central heterocchromia is when there's a ring of a different color around the pupil. Most people are born with this condition due to genetic mutations affecting eye pigment, but it can also happen after an injury or illness. Milkunis developed it after an eye injury as a kid. David Bowie was famous for his different eyes, but it wasn't actually heterocchromia. He was punched in the eye as a teenager, which paralyzed one iris, making it look different. Historically, people with heterocchromia were often thought to have magical powers. In Eastern Europe, they were sometimes accused of being witches. Native Americans believed these people could see into hidden worlds. Number five, no nails for you. People with ania congenita are born without any fingernails or toenails. Not a single one. It's incredibly rare with only a handful of cases documented worldwide. This condition is caused by mutations in the RSPO4 gene. You need to inherit this mutation from both parents. Everything else about their fingers and toes is totally normal. The bones, skin, and even the nail beds are all there. Just no actual nails growing on top. Surprisingly, it's not a major disability. People with this condition can do pretty much everything you can do. They just have to get a bit creative when it comes to scratching an itch. Picking up a coin from a flat surface also becomes surprisingly difficult. On the bright side, they save a fortune on manicures and pedicures. No nail clippers needed, no painful hangails, and zero chance of breaking a nail. A 19-year-old guy from Saudi Arabia lived his whole life without nails. He played sports, finished school, and was totally confident. His family actually had several members with the same condition across multiple generations. It's not considered a disease that needs curing, just an unusual genetic quirk. Number four, double trouble lashes. This rare condition is called disticasis. You have not one but two rows of eyelashes. Only about 1% of people have this genetic quirk. You might think having double eyelashes would be amazing, like built-in falsies. But that second row of lashes often grows inward, meaning they're constantly poking your eyeball. It's like having tiny needles jabbing your eye thousands of times a day. Some people are born with this condition due to a genetic mutation. During development, cells that were supposed to form protective eye tissue became hair follicles instead. Others develop these extra lashes later in life after eye injuries or infections. The constant irritation can lead to redness, swelling, and even serious coral damage over time. People with distasis often get their extra lashes removed through laser treatments or even regular plucking. Number three, bonus neck rib. About one in 100 people are walking around with an extra rib growing right out of their neck. It's called a cervical rib. You're born with it, and most people who have one never even know it's there. This bonus rib grows from one of your neck vertebrae, usually right above your normal first rib. For most people, it causes zero problems. But for others, this extra rib compress on nearby nerves and blood vessels. This can cause tingling, numbness, and pain shooting down the arm. In extreme cases, it squeezes blood vessels enough to cut off circulation. One teenage athlete had her extra rib pressing against her blood vessels, cutting off blood flow to her arm. At first, doctors just brushed it off as minor pain, but then her fingers started changing color and going numb. She ended up needing vascular surgery, all because of a tiny extra rib nobody knew was there. Woolly mammoths often had these same bonus neck ribs, too. Some scientists think this might have actually contributed to their extinction. Number two, one palm line to rule them all. Look at your palm. Most people have three distinct lines running across it, but about one in 30 people only have one single line stretching across their entire palm. It's called a single palmar crease. It used to be called the Simeon crease because it looks similar to what you'd see on a monkeykey's hand, but that name is outdated. This single line forms before birth around 12 weeks into pregnancy. As the hands develop and curl in the womb, sometimes two creases merge into one. Men are twice as likely to have this feature than women, and people of Asian or Native American descent are more likely to have it, too. In most cases, it's just a normal variation, like attached earlobes. However, this single line does appear more often in people with certain genetic conditions like Down syndrome. But having the line alone doesn't mean anything is wrong. Many perfectly healthy people have it. Sometimes it only appears on one hand, and it can run in families. Number one, secret ear hole. You might notice a tiny hole near your ear you never saw before. This little pit is called a pre-uricular pit. About 1% of people in the US have it. The numbers are higher elsewhere. Up to 10% in some Asian and African countries. This tiny ear hole forms during development in the womb. Your outer ear develops from six tissue hills that are supposed to fuse together. Sometimes they don't fuse completely, leaving behind this tiny pit. A Dutch scientist first documented these in 1864, but Renaissance paintings show people with these tiny holes hundreds of years earlier. Most of the time, these little holes are harmless, but occasionally they can get infected if dirt or bacteria get trapped inside. This can cause pain, swelling, and possibly discharge. This feature runs in families, so if you have one, your parents or kids might, too. That's all for today. I'll be making similar videos in the future. Subscribe to see them.