Albinism is a disorder characterized by a lack of pigment in the skin, hair, and eyes. It is an inherited genetic condition caused by mutations in DNA that negatively impact the production of melanin. People with albinism generally appear to have light coloured skin, hair, and eyes in comparison to other members of their family or ethnic background.
The manufacturing process of melanin begins within melanocytes. These cells are located in the bottom part of the skin's epidermis, the part of the eye known as the uvea, the inner ear, hair follicles, and the membrane around the brain and spinal cord. Melanocytes follow the instructions supplied by DNA to build a specialized enzyme called tyrosinase and the amino acid tyrosine.
Sacs called melanosomes take in these enzymes along with the tyrosine and begin a series of chemical reactions which convert the tyrosine into melanin. The specialized enzymes act as a catalyst for the chemical reaction. Once the melanosomes are full of melanin, the melanocytes send the melanin to skin cells, the iris of the eye, and into the hair.
Although there is no cure for albinism, the disorder generally does not affect personality, intelligence, or lifespan. There are some conditions caused by albinism but they can usually be overcome with corrective equipment and lifestyle adjustments. Most people who are affected by albinism can live long and fulfilling lives.
Albinism is a somewhat socially misunderstood condition. People who are affected tend to look quite different and can find themselves alienated or even bullied by peers. Awareness is the first step to eliminating stigmas and fostering inclusion. Here are 15 facts about albinism you probably didn't know.
Albinism is split into two groups, ocular albinism (OA) which affects only the eyes and oculocutaneous albinism (OCA) which affects skin, hair, and eyes. The OCA group has several types based on which genes are mutated to cause the condition and each type has subtypes. People with different types of oculocutaneous albinism can look quite different. There are hundreds of variations of the genetic mutation and new versions continue to be found.
There are currently seven types of oculocutaneous albinism. These are classified as OCA1 – OCA7 and each one involves a different DNA segment which is in some way related to the process of making melanin. There are also several conditions which cause albinism including Hermansky-Pudlak syndrome, Chediak-Higashi syndrome, Prader-Willi syndrome and Angelman syndrome. People affected by these conditions usually have other symptoms some of which can be serious and even life threatening.
In many parts of the world, people with albinism are able to lead fulfilling lives with successful careers and equal opportunities. There are some places where this is not the case and people with albinism face stigmas that can prevent them from reaching their full potential. In parts of Africa these people are outcasts and the lack of school accommodations along with social persecution prevents them from getting profitable jobs or being equal members of society.
In some parts of Africa including Kenya, Tanzania, and Zimbabwe there are dangerous myths involving people who have albinism. Some people believe that the body parts of people with albinism carry good luck. This sometimes leads to the murder and dismemberment of people with the condition. Another dangerous myth is that intercourse with a woman who has albinism can cure HIV. This leads to the violation of women with albinism.
It is commonly believed that people with albinism have pink eyes. This belief is based on a myth and isn't actually true at all. Most people with albinism have eyes in some shade of blue. Less common are people who have hazel or brown eyes depending on how much melanin their body is able to produce.
On rare occasions a person who makes no melanin can appear to have reddish eyes but this is an illusion. In a person with the most extreme form of albinism, the iris can be so lightly coloured that certain lighting conditions can allow the blood vessels at the back of the eye to be seen. This effect can cause the eye to look pink, reddish, or even violet. Even the complete absence of melanin does not cause a red or pink pigmentation.
Vitamin D is known as the sunshine vitamin because our bodies synthesize it with the use of the sun's rays. When ultraviolet B rays come into contact with the skin, a chemical within the skin is turned into vitamin D3. With the help of the liver and then kidneys, this form of the vitamin is transformed into the active form of vitamin D that the body can use.
Since melanin absorbs ultraviolet rays, it slows down the process of the chemical reaction in the skin and affects the body's ability to synthesize vitamin D. People with albinism who make little to no melanin synthesize vitamin D five times faster than people with dark skin. The lack of melanin allows the ultraviolet rays to penetrate the skin more easily allowing more chemical reactions and greater synthesis of vitamin B3.
People with albinism have some level of vision impairment ranging from mild to severe. Common eye problems include nearsightedness, farsightedness, astigmatism, involuntary movements of the eye (nystagmus), or the appearance of eyes moving independently of one another (strabismus). Melanin plays an important part in the development of the eye and affects vision in one of three main areas.
As the eye of a person with albinism develops, there is an increased likelihood that the cornea will curve irregularly. One of the functions of the cornea is to refract light and an abnormal curve will affect the cornea's ability to do that. This causes a distorted image.
The fovea is a pit in the center of the retina which is packed with cones that allow for the detection of colour. Melanin helps the fovea form correctly. A person with albinism might not have a fully formed fovea and may have few cones.
The optic nerves connect the eyes to the brain. Melanin directs developing optic nerves where to go. Half should cross from the eye to the opposite side of the brain while the other half should remain on he same side of the brain. In the absence of melanin, all or most of the optic nerves will cross affecting proper depth perception.
Ultraviolet rays from the sun can damage cells and DNA. When a regular person is exposed to the sun, melanosomes send out more melanin to the skin resulting in a tan. Melanin acts as a sunblock by absorbing ultraviolet rays to protect cells and DNA from sun damage. When there isn't enough melanin to absorb all of the ultraviolet rays, those rays that penetrate the cells cause a sunburn.
People with albinism make little or no melanin and have decreased or non-existent protection against the sun's harmful rays. Those who make some melanin are able to tan somewhat but those who make no melanin can't tan at all. People with albinism will sunburn far more easily than people with normal melanin production. This leaves the skin vulnerable to skin damage, sun burn, and increases the risk of skin cancer.
Oculocutaneous albinism is the most common form of the disorder. The genes for this form of albinism are located on the autosomal chromosomes. We have two copies of autosomal chromosomes because we inherit one set from our mother and one from our father. The dominant set of each of our duplicate genes will manifest itself in our appearance and the function of our bodies.
The genes related to albinism are recessive which means they will not be manifested if the second copy of those genes is not affected. A person with one copy of the defective genes will make enough melanin with the functional set of genes and appear normally pigmented. Such a person is called a carrier because although they don't have the condition, they carry the gene.
While albinism is relatively rare with only 1 in 20,000 cases in some parts of the world, the occurrence of carriers is much more frequent with an estimate of 1 in 70. If one carrier and one unaffected person produce offspring there is no chance of them having albinism, although they may be a carrier. When two carriers produce offspring the likelihood of their child having albinism is 1 in 4.
Not all forms of albinism are created equal. Some people with albinism produce very little or even no melanin. Their skin is very pale, hair is usually a platinum colour, and eyes are generally light blue. Other forms of albinism allow for varied ability to produce melanin and, as a result, people with this type of the condition may have only somewhat lighter complexions with light brown hair and eyes.
Ocular albinism affects primarily the eyes. A person with this form of albinism will usually have close to normal pigmentation of skin and hair but light coloured eyes. Since the presence of melanin in the eye is a vital component to proper eye development, people with ocular albinism are afflicted with the same kind of vision problems as people with other forms of albinism.
While oculocutaneous albinism affects males and females equally, ocular albinism occurs primarily in males. The gene for the most common type of ocular albinism is carried on the X chromosome. Females have two sets of the X chromosome while males have only one X chromosome and one Y chromosome that makes them male. A male needs to inherit only one ocular albinism gene from a carrier mother to have the condition.
Because females have two sets of the X chromosome, they have a backup for any potential defects. In order for a female to have ocular albinism she would need two sets of the altered gene. The only way this would be possible is if her mother was a carrier and her father had ocular albinism. Although this is possible, it is very rare.
While it is difficult to get exact figures, it is estimated that globally one in 17,000 people have some form of albinism. However, the geographic distribution of albinism is not equal around the world. When taken as a whole, in some areas albinism is as rare as 1 in 20,000. In other corners of the planet, the occurrence of albinism is as frequent as 1 in 1000.
If we look more closely, these differences in distribution are even more extreme. Looking specifically at certain forms of albinism and how they affect particular populations is where the numbers truly diverge. The most common form of albinism is OCA2. It is found among 1 in 36,000 of Caucasians in the United States. Among the Kuna Native Americans in Panama it is as common as 1 in 125.
Every creature that makes melanin can have albinism and since all animals make melanin, they can all be afflicted. In the wild, at least 300 species of North American wildlife have had at least one reported instance of albinism. While these animals often struggle in the wild as they are not able to blend in with their surroundings and are sometimes shunned by other members of their species, they are usually helped by people who are in awe of their unique beauty.
In nature albinism occurs in around 1 in 10,000 animals but some species are more affected than others. Albinism seems to be more prevalent in birds with occurrences as common as 1 in 1764. Humans have attempted to sway these numbers with breeding programs aimed at producing more births with the albino gene being manifested. These animals are sought after as unique and expensive pets.
It was once believed that albinism affects intelligence but this is not the case and people with albinism have the same mental acuity as those who are unaffected. One of the reasons why this myth might have come about is that infants with albinism struggle more with eyesight which often leads to developmental delays.
Newborns have fairly poor vision as it is and adding the visual impairment of an eye with albinism results in a dramatic change in the ability to see. Over the first six months of life, the eye of an infant continues to develop and sight improves. Babies affected with albinism see the most improvement in this period of time and continue to have better eyesight in the first few years of life.
While children with albinism never reach normal levels of eye health, they do improve greatly as the eye matures. Babies with albinism may suffer developmental delays but they generally catch up as eyesight improves. There are also devices, exercises, and lifestyle considerations that can be implemented to further assist children with albinism so that they are able to keep up with other children of the same age.
In some communities, myths based on superstition put the safety of people with albinism at risk. These erroneous beliefs are present in cultural attitudes and practices around the world. In an effort to combat these myths and beliefs through a global focus on albinism advocacy, the United Nations' General Assembly established June 13th as the International Albinism Awareness Day.
This was formally put in place on November 18, 2014. The first International Albinism Awareness Day was celebrated on June 13, 2015. This date is commemorated by individuals as well as albinism advocacy groups who host events and offer ideas on how to celebrate International Albinism Awareness Day. Some ideas include posting about the day on social media, hosting events with family and friends, giving presentations at local schools, and sharing personal stories and photos.
The most common type of albinism is the oculocutaneous form which affects the eyes, hair, and skin. There are seven types of oculocutaneous albinism and the condition can drastically range in severity. Some people have no pigmentation of the skin with white hair and light blue eyes while others can have almost normal pigmentation of the skin with brown hair and eyes.
For most people, the production of melanin doesn't change and their pigmentation remains the same over the course of their lives. In some cases people with certain types of oculocutaneous albinism can get slightly darker as they age. This is most likely to happen in people who have the type of oculocutaneous albinism known as OCA1. While the eyes are generally not affected, the skin and hair of these individuals may darken over time.
The coloured part of the eye known as the iris has the ability to open and close the dark part at its center known as the pupil. It does this to allow the ideal amount of light into the eye so that the retina at the back of the eye can collect the picture. In a normal eye, melanin darkens both the iris and the retina so that the iris can block the light and the retina can absorb it.
With a decreased amount of melanin, the iris lets light through and the retina doesn't do a good job of absorbing it. As a result, light scatters in the eye. This can cause discomfort or pain depending on the severity of the situation. This sensitivity to light is called photophobia. Some people with normal pigmentation but light coloured eyes experience this but in individuals with albinism the effect is much more extreme.