
Poliosis runs in the family

This isn’t a trendy style choice, although it does look cool! Poliosis is a rare genetic trait that causes a patchy lack of melanin across the hair. The results can be single highlights like the mother and child above, or sporadic spots of white all over. It isn’t a sign of anything dangerous, but sometimes appears alongside other conditions.
Sunflower eye

Sunflower eye is a type of heterochromia, a genetic defect that causes uncommon or mismatched eye colors. This kind is referred to as central heterochromia, though it’s caused by the same uneven distribution of melanin. The condition affects less than one percent of the population, and can also present after an eye injury.
Poliosis, heterochromia and vitiligo

While all of these conditions are caused by problems with melanin distribution, the odds of them all occurring at once are billions to one. Vitiligo is similar to poliosis, only it affects patches of the skin instead of hair. All of these conditions can be inherited genetically, showing just how different all of us are.
Bifid thumbs

Bifid thumbs are surprisingly common as far as genetic birth traits are concerned. It affects around one in every 1,000 people, causing an extra thumb to grow on the hand. The two thumbs are smaller than one would have been, and each develops part of one fully functional thumb. This means surgery can be complex, as you can’t simply remove one.
Axenfeld-Rieger syndrome

This rare genetic disorder can be diagnosed in numerous ways it can affect the eye. The name describes a group of different genetic variations that overlap into one syndrome, like underdeveloped irises, an uncentered pupil, and opaque rings around the cornea. It also affects the teeth and can lead to glaucoma and permanent blindness if untreated.
Hutchinson-Gilford syndrome – Rapid aging

Hutchinson-Gilford Syndrome, often referred to as progeria, is an extremely rare condition that normally presents at around one year old. It causes rapid aging, first starting with the loss of fat tissue, slowed growth, and hair loss. There is no cure for the condition, but treatments continue to progress, leading to a life expectancy of around 20 years.
Ehlers-Danlos syndrome

Fans of Ru Paul’s Drag Race will recall season 11 winner Yvie Oddly lives with this condition. She demonstrated many of the ways it affects the body, such as overly flexible joints and highly elastic, fragile skin. Ehlers-Danlos causes a mixture of issues and can be passed on to children, though birth itself poses a huge health risk.
Congenital nevus

These are more commonly referred to as birthmarks and are some of the most common skin conditions on Earth. They can either be present from birth, or emerge in the first few weeks of life, and require absolutely no treatment in most circumstances. Sometimes, like the one above, they can resemble some very popular imagery!
Raynaud’s disease in the fingertips

Although this condition looks scary, it’s harmless for most people. You might not even know if you have it depending on where you live, as it causes extreme sensitivity to temperature in the fingertips and toes. As a result, they turn white and often blue when subject to light changes in heat, though they go back to normal when regulated.
Waardenburg syndrome and wide-set eyes

Waardenburg Syndrome causes a person to be born with very wide-set eyes. This is exactly the case for Stef Sanjati, the popular Twitch streamer seen above. It can also cause a striking pigmentation in the eyes, hence why Sanjati’s shine so much, and has also caused deafness in her left ear.
Achondroplasia

This genetic condition affects the proteins that govern growth in the body, resulting in smaller statures, and a larger head relative to the limbs. Celebrities like Peter Dinklage, Warwick Davies, and Vernon Troyer have all spoken openly about their lives with the condition, and how it has affected them in the entertainment industry.
Dermatographia

While doctors certainly wouldn’t recommend doing this even if you don’t have the condition, it’s certainly a bad idea if you do. Dermatographia causes skin to be extra sensitive to scratches, with even a brush causing redness that can take a while to go away. It also gives you a high risk of long-term scarring.
Marfan syndrome

As a rare and hard-to-diagnose condition, Marfan syndrome exhibits slightly differently depending on the individual. There are some common characteristics though, such as as being incredibly tall and thin, with much longer arms proportional to the body. This can cause strain on the cardiovascular system. leading to many health complications.
Uncomfortable hair syndrome

As the name implies, this rare mutation can make life a pain for those with it. It can be easily diagnosed as it causes the hair to be dry and grow outward in all directions, which results in tangles and knots that can’t be brushed out. The tension causes a lot of pain, though it can be treated with good haircare.
Polycephaly

Though it isn’t caused by genetics, this condition still demonstrates how complicated and precise our development really is. It appears when either one embryo fails to split, or two join together, and can lead to surprising results. Those with the condition can have a separate head, and depending on how they joined, can be two separate individuals.
Bam syndrome

With only 100 cases identified across the world, Bam syndrome affects the body in three main ways. The first is the complete absence of a nose, and the second is defects in the eye, such as a lack of tear ducts. The final effect is sexual development, though the gene believed to be responsible for the condition isn’t passed down through parents.
Natural highlights

While this may look like a salon job, it’s something that many have presented since birth! These natural highlights are caused by birthmarks on the scalp, which as we have learned are the result of melanin deposits. When they’re beneath the hair, no melanin is produced for the growing hair, which causes lighter colors.
Hypertrichosis causes lots of hair growth

Managing hair can be difficult, but those with hypertrichosis face an insurmountable task. This incredibly rare genetic trait causes hair to grow pretty much everywhere, including all over the face! There is no known cure, but treatments include standard hair removal techniques, like lasers, waxing, and shaving.
Sirenomelia

As the name implies with its allusions to the mythical siren, children born with this condition have only one tail-like lower limb. Only around 300 cases have ever been documented, making this an incredibly rare mutation. Due to the formation of the limb, the body can’t properly provide it with nutrition, leading to premature death in most cases.
Natural Chimeras

Genetics is extremely complicated and complex, and often humans can have genotypes that are completely separate from the rest of their DNA. There have been cases of people having multiple blood types from resorbing twins in the womb, and like seen above it can often affect skin pigments! Conditions like intersexuality also fit under the generic definition of a chimera.
An extra mini-toe

While this may look like an ingrown toenail, or perhaps even just a skintag, it’s a tiny independent digit. Some variation of an extra digit on either the hands or feet isn’t that rare and they’re often removed with ease. As you can see, this one is complete with its tiny toenail!
Crazy cowlicks

These frustrating and difficult-to-tame hair features are common and affect both men and women. They’re decided by genetics, so you either have them or you don’t, and some unfortunate people are born with multiple! It takes a good deal of styling and product to correct a stubborn cowlick, god forbid having to sort two of them.
Colomba pear pupils

Many genetic conditions can affect the eyes, and this one is an incredibly distinctive example. Though it can affect both eyes, this woman has it only in one. It’s caused by a missing section of tissue in the iris, which can lead to complications with vision, though it can be treated fairly easily!
Ectrodactyly

Sometimes called cleft hand, this condition causes developmental issues in the hands and feet. It can be presented in several ways, but the picture above shows some characteristics they share. Webbing and additional growths can be removed, and surgery can be performed on the hand to restore some dexterity.
Persistent Pupillary Membrane

PPM can result in several incredible shapes across the pupils and iris. It’s a congenital defect, occurring when fetal tissue remains after development that has not been used for another part of the eye. It’s one of the most common eye defects and rarely causes vision issues.
Stahl’s ear

Many have pointed out the similarities between Stalh’s ear and those of an elf, as there seems to be a point present! This is a condition that’s present from birth in some people and is caused by an extra fold in the cartilage. The picture above is from one of a set of twins, the others had formed normally.
Cleft lip

Cleft lips are a very common birth defect, affecting around one in every 600 children. They occur during fetal development when the two sides of the lips don’t fully join. They are stitched together soon after birth, but the gap can range in size. Actor Joaquin Phoenix was born with a cleft lip, making his face even more distinctive.
Epidermodysplasia verruciformis

This rare genetic disease causes a susceptibility to HPV. Each of the individual growths is a separate infected area, as there are many different kinds of HPV we come into contact with, but with a healthy immune system, they pose no risk. Those with this autoimmune disease, however, grow these papules.
Severe combined immunodeficiency disorder

Popularised by the 1976 film The Boy in the Plastic Bubble, this condition refers to a group of auto-immune diseases. It causes no visual issues, and babies born with SCID appear completely healthy. The genetic abnormalities significantly impair the production of white blood cells, meaning the body has no means to fight infection.
Proteus syndrome

This was one of the conditions that Joseph Merrick, otherwise known as the Elephant Man, was diagnosed with. It causes the organs and skin to grow out of proportion with the rest of the body, though it seems to have no specific rhyme or reason. This often causes unpredictable growths that usually begin to form after a few months.
Alkaptonuria the black bone disease

Those born with alkaptonuria might not realize this until later in life. It causes an issue with how the body breaks down certain kinds of acids, which will first appear in the urine. It becomes black when exposed to oxygen, as do the eyes, skin parts, and joint connective tissue.
Anencephaly

This is a rare condition that affects around one in every 4,600 babies born in the United States. Children born with anencephaly lack a significant portion of the brain and skull, and as a result, they often die shortly after birth. It’s not exactly sure what causes it, though it is likely some combination of environmental and genetic factors.
Talipes

Talipes are one of the most common foot defects and are twice as likely to appear in males. It can involve one or both of the feet and causes them to point curve inwards by the ankle, resulting in its more common name “club foot”. It can correct itself as the child grows, though some cases might require surgical correction.
Neurofibromatosis

This is an incredibly complex condition that scientists are still working to understand. There are two different forms, depending on whether it is diagnosed in childhood or early adulthood. The main symptom is the development of tumors all over the nervous system, which are mostly benign but can cause issues if they grow in vital areas.
Diprosopus

This condition is often misunderstood as a form of conjoined twins, but it’s actually a congenital disorder affecting a single fetus. It’s caused by the Sonic hedgehog protein, named by some eccentric biologists responsible for facial feature development. This means most can live completely normal lives.
Otocephaly

Children born with otocephaly rarely live past their first few days, due to the severe nature of their genetic condition. It causes abnormality in the development of the nose, jaw, and much of the skull, often resulting in issues that are incompatible with life. Because of its rarity and lethality, doctors still study it.
Harlequin ichthyosis

Often referred to as simply harlequin syndrome, this genetic condition results in the excessive production of skin. Only a few children manage to survive childhood, due to the increased risk of infection, dehydration, and trouble regulating their temperature. A lot of care is required, as they need bathing and exfoliating daily.
Polymelia

This condition is much more common in animals but is known to appear in humans too. It causes the growth of extra lower limbs, and although they contain bones, muscles, and blood, do not function. This was one condition known to be caused by thalidomide, a medication that gained popularity in the 60s and 70s.
Fibrodysplasia ossificans

This condition essentially petrifies the body over time, making it a terrifying yet fascinating indication of how our bodies work. Excessive bone production leads to muscles and ligaments being eroded and replaced with hard minerals. The ACVR1 gene, which creates bone protein, is known to be overactive in patients.
Williams syndrome

Caused by a chunk of around 27 missing genes, this developmental disorder results in a specific appearance and temperance. Williams’ patients are known to be bubbly, and outgoing and often have a passion for music. It is characterized by a wide mouth, small teeth, and an upturned nose.