Learn About These Unique Genetic Mutations in Humans
The human body’s development can be a tricky business. Different DNA sequences and genomes all play huge roles in things like immune responses and neurological capacities. The genomes people possess are deciding factors in everything all the way down to the color of their eyes, hair and skin tone. When a mutation happens in a genome, it can lead to some unique situations when it comes to how a person’s body looks, how their mind works and how they’re able to use their body.
Uner Tan Syndrome
Uner Tan syndrome was named after a famed Turkish evolutionary biologist after he documented a family living with this condition. People with Uner Tan walk on all fours and often have limited mental capacities and language skills.
Known colloquially as "werewolf syndrome," hypertrichosis is a rare genetic mutation that leads to excessive hair growth on all parts of the body. Both males and females can develop the condition, and only around 40 people with the disorder have been documented across the world.
The autosomal recessive skin condition better known as "treeman syndrome" happens due to a human papillomavirus (HPV) infection. While the body is dealing with HPV, the infection can lead to skin growths that resemble rough tree bark or wood.
Severe Combined Immunodeficiency Disorder
When genetic mutations alter the functional development of both T and B cells in a person’s body, they can develop severe combined immunodeficiency (SCID). This creates problems when it comes to being out in a world full of germs because the disorder makes people highly susceptible to getting infections.
Progeria — or Hutchinson-Gilford progeria syndrome (HGPS) — is an autosomal genetic condition that is found in 1 in every 4 to 8 million people. The genetic disorder causes a person to age significantly faster than the average person.
Lesch Nyhan Syndrome
Lesch Nyhan syndrome is a hereditary genetic mutation that happens when there is a deficiency of the gene-encoded enzyme HGPRT in a person’s body. This enzyme is responsible for the proper function of uric acid.
This congenital disorder happens in the womb when a person’s hands don't develop properly. Typically, the middle fingers on the hand don’t form at all, but sometimes only one may be missing. This results in a split appearance in the hand.
The rare Proteus syndrome is a genetic mutation that causes tissues to grow abnormally. It also encourages tumor growth throughout an affected person’s body. Named after a Greek god that could change his shape, Proteus syndrome is rare and affects fewer than 1 in 1 million people across the world.
A rare genetic syndrome that isn’t seen but is smelled is trimethylaminuria (TMAU). Also known as "fish odor disease," the defect happens when a person’s body’s production of flavin-containing monooxygenase 3 is compromised. This results in metabolic impairment.
Marfan syndrome is a condition that results in abnormalities in a person’s connective tissues. People who have this disorder are often very tall and thin and may have a problem keeping fat on their bodies. It’s been suggested that Abraham Lincoln had the condition. Marfan syndrome can also lead to scoliosis in some people.
When the rare genetic disorder anencephaly occurs, a fetus’s brain, skull and scalp develop abnormally — or sometimes not at all. This condition is one of the more tragic, as almost all babies born with it don’t live more than a few days past birth.
Tetrachromacy is a condition that occurs when a person develops a fourth cone of vision in their eye. This leads to the person being able to see many more colors than the average human being can.
The phenomenon of distichiasis, otherwise known as double eyelashes, might be enviable in some circles, but it's actually a very rare genetic disorder caused by a gene mutation in the womb. Distichiasis can affect both eyes and all four lash lines, or it can be present in just one area of the lash line.
It may be a trope in comic books, but cyclopia isn’t entertaining. With this condition, a baby is born with only one eye. The congenital defect happens in the womb when the two eye sockets fail to separate during early development.
Vestigiality usually refers to traits or features that used to exist in living creatures (or potentially existed in those creatures, humans included) but phased themselves out of the evolutionary picture because they were no longer necessary for survival. The most notable of these in people is the tailbone — our early ancestors had tails. Some people still form tails.
Just as the name suggests, gigantism is a genetic mutation that causes a person to grow much larger than the average human being. The rare disorder occurs when the body’s growth hormone production increases, causing the body to accelerate growth during or directly after a person hits puberty.
Human eyes usually aren’t that adept at seeing underwater because of the limited amount of refracted light that's able to get through. One rare genetic disorder that affects a small number of people in Thailand makes them able to see everything underwater quite clearly.
Polymelia is categorized as a birth defect that causes a fetus to develop extra limbs. It's also theorized that the limbs were once part of a conjoined twin that was absorbed while in utero. The extra limbs are, in many cases, significantly deformed and may not function.
The phenomenon of having two heads isn't just in myths or fairy tales. The rare genetic disorder, although mostly attributed to animals, has happened in humans. In humans, the condition generally occurs with conjoined twins that share the same body or conjoined twins that are joined by the head, ear or brain.
Reptilian atavism is another genetic mutation that isn’t visual but instead occurs inside a person’s body. That doesn't make it any less odd — or interesting. The condition is so rare in humans that there have only been a couple of cases documented in the history of the world.
Congenital methemoglobinemia is a condition that affects the appearance of a person's skin, lips and nails. This autosomal defect causes a person's skin to turn blue. It’s hereditary and is so rare that the number of cases in the world remains unknown.
The rare condition called hyperdontia occurs when more teeth develop in a person’s mouth than usual. Supernumerary teeth are generally found in people who also have the rare genetic disorder Gardner's syndrome.
Unlike other genetic mutations that cause extra limbs or heads, diprosopus doesn't involve a conjoined twin. This genetic disorder is characterized as creating "craniofacial duplication," meaning that certain parts of the face or head are doubled (or duplicated.)
Fibrodysplasia Ossificans Progressiva
Fibrodysplasia ossificans progressiva, otherwise known as FOP, is a genetic defect that is present in fewer than 1 in 2 million people worldwide. Unlike many other genetic defects, FOP is a disabling condition that has no treatment or cure.
Congenital insensitivity to pain with anhidrosis (CIPA) is a genetic condition in which the person with the defect has a limited ability — or no ability at all — to feel pain. It’s classified as an autosomal recessive disorder and is passed down from a person’s parents.
Brittle bone disease is a rare genetic disorder that causes the bones in a person’s body to be especially susceptible to breaks, even with very little force applied. The disease can range in severity and can be attributed to problems with collagen production and connective tissue.
Treacher Collins Syndrome
The autosomal dominant genetic disorder Treacher Collins syndrome, often shortened to TCS, is caused by a new mutation in a person’s genes. This means a person’s parents don’t pass them the gene; however, the condition can be hereditary in rare cases. TSC causes a wide array of physical deformities, often involving the ears, eyes, chin, cheekbones and other parts of the face.
You may know a chimera as a mythological creature or associate the term with animals, but instances of the genetic abnormality do exist in humans. The mutation occurs when certain strands of cells in the body become muddled and blood mixes in the wrong way. It causes a person to carry two different sets of DNA.
Myostatin, otherwise known as "double muscle mutation," is characterized by the presence of double the muscle that a person’s body would normally have. The most notable and known cases are those in small children who are super-strong for their age and expected abilities.