Many people think mutations are just the stuff of superhero movies. However, in reality, genetic changes are much more common than you might think.

Below are some of the unusual genetic traits and their estimated prevalence.

Sociopathy

Probability: approximately 1 in 25

Sociopathy is associated with antisocial personality disorder. People with this condition often ignore rules, act impulsively, and may harm others without feeling guilty. Research suggests that a certain genetic predisposition to this disorder may indeed exist.

Psychopathy

Probability: approximately 1 in 100

Psychopathy is considered a more severe form of antisocial behavior. It is characterized by a lack of empathy, a sense of superiority, and a tendency to manipulate. Historically, examples of people with these traits have been reported, including some criminals and leaders of destructive cults.

Autism

Probability: About 1 in 59

Autism is a developmental disorder that can make it difficult for a person to interact with others and communicate. Symptoms typically appear in early childhood and can vary greatly in severity.

Birth of Twins

Probability: About 1 in 85

Twins can be identical or fraternal. In the former case, twins share the same genetic makeup, while in the latter, they develop from two different eggs. In rare cases, even double paternity is possible.

White Patches on the Skin (Vitiligo)

Probability: About 1 in 120

Vitiligo is a condition in which patches of skin lose pigment and become lighter in color. Sometimes, the hair in these patches also lightens. Famous people with this condition include singer Michael Jackson and model Winnie Harlow.

Different Eye Colors

Observation Rate: About 1 in 167

Heterochromia is a condition in which the eyes are different colors or shades of blue. It can be congenital or develop due to injury or disease. Famous people with this condition include David Bowie, Benedict Cumberbatch, and Mila Kunis.

Extra Fingers

Observation Rate: About 1 in 500

Polydactyly is the presence of an extra finger or toe. This finger is usually smaller than the others and is sometimes surgically removed. This condition can be inherited.

High IQ

Observation Rate: About 1 in 600

A very high IQ is relatively rare. Generally, an IQ above 140 is considered a sign of exceptional intellectual ability.

Down Syndrome

Observation Rate: About 1 in 700

Down syndrome is caused by an extra chromosome 21. Characteristic developmental facial features may accompany it. The likelihood of having a child with this syndrome increases with the mother’s age.

Extra Limbs

Occurrence: approximately 1 in 1,700

Polymelia is a rare anomaly in which a person is born with extra arms or legs. Sometimes this is due to embryonic development, when one twin does not fully develop.

Microcephaly

Occurrence: approximately 1 in 5,000

Microcephaly is characterized by a baby being born with a head that is smaller than normal. The causes may be genetic or related to infections and other factors during pregnancy.