Most people have an innie belly button, while outies are rarer, appearing in only about 10% of adults.

Despite common myths, belly button shape isn’t determined by how the umbilical cord is cut but rather by how the scar heals.

Some people choose surgery to change an outie to an innie, though there’s nothing wrong with having one—it’s simply a matter of personal preference.

Most people don’t think twice about their eye color, but for those with heterochromia, it’s not so simple.

This rare condition comes in three forms: complete, central, and partial.

In complete heterochromia, each eye is a distinctly different color.

While usually caused by genetics, it can also result from medical conditions or injuries.

In the U.S., fewer than 200,000 people have this striking trait.

Golden blood isn’t actually golden—it’s an extremely rare blood type that only about 40 people in the world have.

Scientifically, it means the person lacks all Rh-blood cell antigens.

Because of this, their blood can be used as a universal donor for those with rare Rh types.

This makes them incredibly valuable to the medical community, as their donations can be lifesaving for individuals with uncommon blood groups.

While most people have to manage their cholesterol levels carefully, a rare mutation in the PCSK9 gene allows a select few to bypass this concern entirely.

This gene plays a key role in regulating cholesterol, and in extremely rare cases—only found in two people—it is entirely inactive, preventing high cholesterol altogether.

Some individuals have a single mutation that still helps keep cholesterol low, though not as effectively.

Having this genetic advantage would certainly make heart health much easier to maintain!

You’ve probably felt your fingers tingle when exposed to cold weather, but for some, the reaction is more extreme.

Their fingers may turn white and go numb due to reduced blood flow, a condition triggered by cold temperatures or stress.

It can look as though their hand has been dipped in white paint, making you wonder if they can still feel their fingers—or if they might just fall off!

Although it may resemble an ear piercing, this small hole or dimple above the outer ear is actually a congenital condition.

Typically found where the ear meets the head, it’s usually harmless but can sometimes become infected.

This rare trait occurs in less than one percent of the population in the West.

Some scientists speculate that it could be a remnant of gill structures from early evolution—though, unfortunately, it won’t help you breathe underwater!

Our ability to perceive color comes from three types of cones in our eyes, but a rare group of people known as “tetrachromats” have a fourth cone.

This allows them to see up to 100 million colors—far more than the average person

While this might sound incredible, it can also lead to sensory overload.

Interestingly, despite their enhanced color vision, one tetrachromat shared that her favorite color is simply white.

Albinism isn’t just one condition—it comes in different forms

Ocular albinism primarily affects the eyes but can also influence hair and skin pigmentation.

It leads to light-colored eyes, reduced vision, and sensitivity to light.

According to the Vision of Children Foundation, this rare condition occurs in about 1 in 50,000 people.

No, this woman isn’t an elf, but her ear shape is due to a condition called Darwin’s tubercle.

This trait is more common in Spanish, Indian, and Swedish populations, though its exact cause remains unclear.

On the plus side, if she ever wanted a seasonal job as Santa’s helper, she wouldn’t need fake ears!

Many people turn to eyelash extensions for fuller lashes, but some, like this girl, naturally have multiple rows due to a condition called distichiasis.

This can result in a full second set of lashes or just a few extra ones in a separate row.

Famed actress Elizabeth Taylor had this rare trait, often mistaken for naturally thick lashes.

However, before feeling envious, keep in mind that distichiasis can lead to tearing, irritation, and even vision issues.

This rare trait makes “super-tasters” highly sensitive to certain flavors, such as bitterness, sweetness, and saltiness.

Because their taste buds are more reactive, they often dislike spicy foods, as they also experience heightened sensitivity to pain.

While you may know several people with red hair, natural redheads are quite rare, making up only about two percent of the global population.

This trait is more common in individuals with ancestry from northern and western Europe.

Since red hair is a recessive gene, both parents must carry it for a child to inherit the trait.

Despite their frequent presence in American pop culture, redheads remain a small percentage of the population.

Have you ever broken a bone? If so, you might envy those with a rare gene mutation that makes their bones nearly unbreakable.

This mutation affects the production of a protein responsible for bone density.

Its significance became clear when a man walked away from a serious car accident without a single fracture.

Researchers later discovered that his bones were eight times denser than those of the average person.

While some traits may seem rare, truly uncommon features like grey eyes are even more elusive.

According to World Atlas, less than one percent of the world’s population has grey eyes, which result from low melanin levels in the front layer of the iris.

While meeting someone with grey eyes is rare, they are more common in regions where green eyes are prevalent.

The only eye colors rarer than grey are red or violet, which occur due to specific genetic conditions.

If you’ve endured the discomfort of wisdom tooth removal, you might be envious of those born without them.

About 20 percent of the population naturally lacks wisdom teeth, sparing them from the hassle of extractions.

The occurrence of wisdom teeth varies by population—100 percent of Indigenous Mexicans are born without them, while nearly all Tasmanian Aborigines have them.

This natural variation has saved many from the pain of impacted teeth and surgery.

You might have a rare body feature called the palmaris longus, a muscle that helped our ancestors climb trees.

While it’s still present in some people, many no longer use it functionally.

To check if you have it, place your arm flat on a surface and touch your thumb to your pinky.

If the palmaris longus is present, the muscle will pop out visibly from your wrist.

While it’s used in tendon grafts for medical procedures, it doesn’t serve a functional purpose for most people today.

People like Nikola Tesla, Margaret Thatcher, and Winston Churchill shared a rare trait: the DEC2 gene, which allows them to complete sleep cycles in less time than most.

This genetic advantage means they could function on very little sleep with minimal negative effects.

Between one and three percent of the population have this “clock gene,” which extends their waking hours and may have contributed to their remarkable achievements.

While everyone has the PCSK9 gene, a small percentage of people have a deficiency in it, which drastically reduces the risk of heart disease by up to 90%.

For those individuals, managing cholesterol levels is far less of a concern.

Having this deficiency would ease a significant health worry.

It’s possible to inherit this trait even if heart disease runs in the family, as genetics can vary greatly among individuals.

This could offer peace of mind, knowing they have a genetic advantage in terms of heart health.

While inactive myostatin genes are well-known in mice and cattle, there have only been a few documented cases in humans.

This genetic condition causes the development of exceptionally strong muscles.

Children born with this mutation typically have lean, well-defined muscles from an early age.

Those with this condition are significantly stronger than children of similar ages.

It’s incredibly rare, and researchers still have limited understanding of its long-term effects.

As these children grow older, ongoing research will help shed light on how the condition might impact them later in life.

While grey eyes are the rarest eye color, blue eyes are also relatively uncommon, present in only about eight percent of the global population.

There’s a common belief that people with blonde hair tend to have blue eyes, a link that can be traced back to a single ancestral mutation.

This genetic mutation, which occurred between 6,000 to 12,000 years ago, is the origin of blue eyes worldwide.

Blue eyes are notably more common in Scandinavian countries, where historical genetic influences have made this trait more prevalent.

Morton’s toe, also known as Greek feet, is a condition where the second toe is longer than the big toe.

It’s present in about ten percent of people, and interestingly, the Statue of Liberty also displays this characteristic.

The term “Greek foot” comes from its prevalence in ancient Greek sculptures, where it was considered an idealized form.

This aesthetic preference carried through Roman, Renaissance, and later art, shaping cultural standards of beauty over time.

A counterclockwise hair whorl, found in only 8.4 percent of people, is a rare feature that might not be immediately noticeable.

Interestingly, left-handed individuals—about 10 percent of the population—are more likely to have a counterclockwise whorl.

Next time you’re around, take a look at people’s hair—chances are, you might spot a unique and rare trait that’s more common than people realize, and it could be a fun way to see just how special someone is!

If you’ve ever sneezed when stepping into bright sunlight, you could be part of the 25 percent of people with a condition called the photic sneeze reflex (PSR).

This quirky response to sunlight is harmless for most but can pose risks, especially when transitioning from dim light (like tunnels) to bright sunlight while driving.

If you’ve experienced this reaction, you might have PSR and not even know it!

Have you ever noticed the lines on your palms forming intricate patterns?

Some people have a rare feature known as a simian crease or simian line, where they have a single line running across their palm instead of the usual multiple ones.

This makes palm reading much simpler for those individuals!

Found in only about 1.5 percent of people on at least one hand, the simian crease is a unique and rare variation in palmistry.

You might not think about it often, but there are three primary types of fingerprint patterns: arches, loops, and whorls.

Arched fingerprints are the rarest of them all.

Everyone typically has a unique combination of these patterns across their fingers, and it’s even possible to have different shapes on each finger.

These distinctive fingerprint patterns aren’t just for identification—they also help us grip objects better, thanks to the ridges that form them.

It’s amazing how something as seemingly invisible as fingerprints can play such an important role in both our daily lives and personal identification.

Dextrocardia is a rare congenital condition where about one in every 12,019 people is born with their heart on the right side of the chest instead of the left.

While it typically doesn’t cause major health problems, it can affect the positioning of other organs, potentially leading to issues like digestive blockages.

For most people with dextrocardia, life goes on as usual, and they’re often told their heart is in the right place—quite literally.

However, the shifted heart position may sometimes cause digestive challenges due to the rearrangement of internal organs.

Amish communities, known for their isolated lifestyle, have a fascinating genetic trait that was uncovered in a 2017 study: a mutation that prevents blood clots from forming.

This genetic variation can extend their lifespan by up to ten years and reduces the risk of developing chronic illnesses, such as heart disease.

Individuals within Amish communities who carry this mutation may experience longer life expectancies compared to the general population, thanks to their body’s ability to avoid the dangers associated with blood clotting.

Some individuals have a rare genetic disorder that causes a persistent and unpleasant body odor, often resembling the scent of rotting fish.

This condition, known as trimethylaminuria or “fish odor syndrome,” is caused by the body’s inability to break down trimethylamine, a compound found in certain foods.

As a result, the compound is released through sweat, urine, and breath, causing the strong odor.

Fortunately, this condition affects less than one percent of the population, making it quite rare.

While there is no cure, managing the diet and using specific treatments can help reduce the symptoms for those affected.

Ambras syndrome, or hypertrichosis universalis, is a rare genetic condition that causes excessive hair growth all over the body.

Individuals with this condition may experience thick, dense hair covering large areas, including the face and body, from a very young age.

The condition is due to a mutation in the gene that affects the signaling processes responsible for hair follicle development.

Historically, Ambras syndrome has been extremely rare, affecting only about 50 people since the Middle Ages.

The condition has been documented throughout history, with some individuals even being featured in sideshows due to their unique appearance.

While the syndrome is not harmful, it can lead to social and psychological challenges for those affected.

Progeria, also known as Hutchinson-Gilford Progeria Syndrome (HGPS), is a rare genetic disorder that causes accelerated aging, with symptoms often appearing within the first two years of life.

Children with Progeria experience rapid aging effects such as excessive hair loss, thinning skin, joint stiffness, and premature wrinkling.

While they may appear elderly, their intellectual development and motor skills remain normal.

Sadly, individuals with Progeria typically have a life expectancy of only 13 to 20 years due to complications like heart disease and stroke, which are common in older adults.

Despite ongoing research, there is currently no cure for the condition, though scientists are exploring treatments that might slow its progression.

Sherpas and other native high-altitude populations, such as Tibetans and Nepalese, have long been known for their extraordinary ability to thrive in environments with low oxygen levels, such as the heights of Mount Everest.

This remarkable tolerance to high altitudes is believed to be the result of a genetic adaptation known as the “superathlete gene.”

Research suggests that this gene, which enhances the body’s ability to distribute oxygen more efficiently, traces back to the Denisovans—an ancient group of humans who lived in mountainous regions of Asia around 40,000 years ago.

The genetic traits inherited from the Denisovans enable Sherpas and similar populations to maintain endurance and perform physically demanding tasks at altitudes where others might struggle with altitude sickness.

Marfan syndrome is a genetic disorder that impacts the body’s connective tissue, which provides strength and elasticity to organs and structures.

Individuals with this condition often have a distinctive appearance, characterized by being tall and slender with long limbs and fingers.

This syndrome can lead to a range of health issues, particularly affecting the heart, blood vessels, eyes, and skeleton.

A common complication is the weakening of the aorta, the main artery that carries blood from the heart, which can lead to life-threatening cardiovascular issues.

Additionally, people with Marfan syndrome may experience joint problems, such as bones that dislocate easily, as well as early-onset arthritis.

The genetic mutation causing Marfan syndrome occurs in about one in 5,000 people, and while some individuals may have only mild symptoms, others may experience more severe complications that impact their quality of life and longevity.

HIV has caused a global epidemic since it was first identified in 1981, leading to millions of deaths.

However, a small percentage of individuals, particularly those of Northern European descent, possess a rare genetic mutation known as CCR5 delta 32, which provides resistance to HIV.

This mutation affects the CCR5 gene, which codes for a receptor that HIV uses to enter human cells.

Individuals with the CCR5 delta 32 mutation have a defective version of this receptor, preventing the virus from entering and infecting their cells.

As a result, they are naturally resistant to HIV infection.

Scientists have been investigating this genetic trait in hopes of developing treatments or cures for HIV.

Research has included attempts to replicate the mutation in people living with HIV, with experimental approaches such as stem cell therapy showing promising results in some cases.

Symbrachydactyly is a rare congenital condition in which a person is born with fewer than five fingers on one or both hands.

This condition typically occurs due to inadequate blood flow to the developing tissues in the womb, leading to underdeveloped or missing fingers.

Most individuals with symbrachydactyly have four fingers on the affected hand, and the pinky finger is often absent, though other variations may occur.

While the lack of a pinky finger might seem to pose a challenge to dexterity, many individuals with symbrachydactyly adapt well to their condition.

The thumb, being crucial for grasping and manipulation, often helps compensate for the missing digit.

Through various techniques, many individuals with this condition find ways to perform everyday tasks effectively, demonstrating remarkable adaptability and resilience.

Anisocoria is a condition where a person has unequal pupil sizes, with one pupil being larger and fixed while the other functions normally.

This can create the appearance of one eye having a larger pupil and the other a smaller one.

For most individuals with anisocoria, the condition is harmless and not a cause for concern.

However, the noticeable difference in pupil size can sometimes lead to misconceptions, with others assuming the person may be under the influence of drugs or experiencing a health issue.

Despite this, the condition is often benign and may even be seen as an interesting or unique feature by some.

Poliosis is a condition where white or grey patches appear in the hair due to a lack of melanin in the affected hair follicles.

This creates a striking contrast and is often seen in characters like Sweeney Todd, who is known for his signature grey streak.

For those with natural poliosis, this distinct feature is an unexpected trait that sets them apart.

While some may opt to dye their hair to achieve a similar look, people with poliosis often find their appearance draws attention, sparking curiosity about the genetic traits that contribute to this unique characteristic.

Vitiligo is a condition where patches of skin, hair, and sometimes nails lose their pigmentation due to a deficiency in melanin.

The resulting lighter patches can create unique patterns, often resembling a mask-like appearance, which some may compare to a superhero’s mask.

Michael Jackson famously dealt with vitiligo, initially concealing it with clothing and later using skin-bleaching treatments to even out his skin tone as the condition progressed.

His iconic glove was originally worn to cover the patches on his hand caused by vitiligo.

Phalanges are the bones found in the fingers and toes.

Occasionally, some individuals may have an extra phalange in their thumb or other digits, though it may be small and not easily noticeable.

The term “phalange” might also bring to mind the humorous alias “Regina Phalange” used by Phoebe Buffay in the TV show Friends.

While the character is fictional, in anatomical terms, phalanges are essential components of the skeletal structure in our hands and feet.

Typically, when forming a fist, the knuckles align next to each other.

However, some individuals may have a unique trait where the middle knuckles are positioned lower than the others.

This rare occurrence is often the result of having a double-jointed knuckle, which can cause the knuckle to bend in a way that gives it an unusual appearance.

Though it may seem like the person had punched a wall forcefully, this condition generally affects only one hand and typically doesn’t cause significant issues, aside from potentially making it more challenging to deliver a strong punch.