Albinism in humans

Albinism (from Latin albus, meaning "white") is a lack of pigmentation in the eyes, skin and hair. It is an inherited condition resulting from the combination of recessive genes passed from both parents of an individual. This condition is known to affect mammals, fish, birds, reptiles, and amphibians.

File:AlbinoWhiteTailDeer.jpg

This rare, newly-born, albino White-tailed deer exhibits the pink eyes typical of most albino animals. In the wild, with no protective coloration, this deer would be easy prey.

Genetics

The gene which results in albinism prevents the body from making the usual amounts of a pigment called melanin. Albinism is typically categorised as Tyrosinase positive or negative. In cases of Tyrosinase positive albinism, the enzyme tyrosinase is present but is unable to enter pigment cells to produce melanin. In tyrosinase negative cases, this enzyme is not produced.

There are many genes which are now scientifically proven to be associated with albinism (or better: alterations of the genes). All alterations, however, lead to an alteration of the melanin (pigment/coloring) production in the body. Melanin helps protect the skin from ultraviolet light coming from the sun (see human skin color for more information). Organisms with albinism lack this protective pigment in their skin, and can burn easily from exposure to the sun as a result. Lack of melanin in the eye also results in problems with vision unrelated to photosensitivity.

Individuals with full albinism (called albinos) generally have pale yellow to white hair, and pinkish-white skin. In many organisms, the eyes of an albino appear red due to the underlying blood vessels showing through where there is not enough pigment to cover them. In humans this is generally not the case, as a human eye is quite large and thus produces enough pigment to lend opacity to the eye. Despite this, completely red eyes resulting from a lack of melanin to cover the underlying blood vessels are not unknown in humans.

Vision aside, albinos are generally as healthy as the rest of their species, with growth and development occurring as normal. Many organisms, however, lose their protective camoflauge and are unable to conceal themselves from their predators or prey. The survivability rate of albino animals in the wild is usually quite low. The largest problem human albinos face is social, as the condition usually is a source of torment during adolescent years.

As albinism is a recessive gene, the chance of albino offspring resulting from the pairing of an albino with a non-albino is very low and is discussed below.

Visual problems associated with albinism

People with albinism always suffer from impaired vision. While an albino may suffer from a standard eye affliction (astigmatism, near-sightedness, etc), the general problem arises from a poorly-developed retina and abnormal nerve connections between the eyes and brain. It should be noted that it is the presence of these abnormalities that medically define albinism. While the actual effects of this condition are generally difficult to describe to non-albinos, one can imagine it as seeing at a lower resolution. Additionally, most albinos suffer nystagmus (a rapid, involuntary "shaking" of the eyes).

Individuals with these conditions may be helped by the use of glasses and low-visual aids such as magnifiers, as well as bright but angled reading lights, but their vision cannot be corrected completely. Although surgery is possible on the ocular muscles, effectively simulating (to a limited degree) the improvements in the albino's vision that often come with age, the gain is generally thought to be out-weighed by the trauma.

The lack of pigment in the eye generally leads to ocular photophobia or hyper-photo-sensitivity. This is due not so much to the iris allowing stray light to enter the eye, as to a lack of pigment within the eye, allowing light to refract within the eyeball. A good analogy would be taking a picture with a film camera that is painted white within, rather than black. Such sensitivity generally leads to a dislike of bright lights, but does not prevent people with albinism enjoying the outdoors. They should avoid prolonged exposure to bright sunlight regardless, as their skin is particularly susceptible to sunburn.

Culture

Snowdrop, an albino African Penguin, born at Bristol Zoo (England), died in August 2004. No other zoo in the world had an albino penguin and only two or three have ever been reported in the wild. Snowdrop would normally have looked like the background penguins.

Myths and superstitions

Due to Albinism's effect on one's outward appearance, cultures around the world have developed many myths and superstitions regarding albinos.

Zimbabwe, currently under the strain of an HIV epidemic, has developed a myth that sleeping with an albino woman will cure a man of the disease. This has led to many albino women in the area being raped.

In Jamaica, albinos have long been denigrated and regarded as cursed. In recent times, the albino dancehall singer Yellowman has helped to end this negative stereotype.

In literature

Several works of fiction have featured evil pale-skinned, platinum-blonde characters, including Michael Moorcock's Elric, The Twins from The Matrix Reloaded, Draco Malfoy from the Harry Potter series of books, and Silas in Dan Brown's Da Vinci Code.

See also: List of albinos

Bristol Zoo was the home to a very rare albino African penguin named Snowdrop. Snowdrop was hatched at the zoo in October 2002 and died in August 2004. For many years, a unique albino gorilla named Floquet de Neu (Snowflake) was the most famous resident of the Parc Zoològic de Barcelona.

Medical science and toxicology, for better or worse, often take advantage of the standardized lack of pigment in albino animals in testing for materials' chemical properties. An example of such a test is the test for corrosiveness, which is a skin exposure test performed on albino rabbits.

Albinos are often the target of insensitive jokes in Western culture. For example, the movie Me, Myself and Irene featured an albino character who was referred to by the nickname "Whitey", and was used as the butt of several jokes. Several cheap jokes have also been made on The Simpsons, with Homer calling Edgar Winter and his brother Johnny a couple of "chalk-faced goons" and running them over with a hearse.

Publications

Albino Animals by Kelly Milner Halls. Darby Creek Publishing (March, 2004) ISBN 1581960123

External links

The UK Albinism Fellowship
NOAH The National Organization for Albinism and Hypopigmentation US
Albinism in Popular Culture
Biblical references - William Blake's Ancient of Days was based upon the Revelation of St John the Divine, 1:14: *:"His head and hair were white like wool, as white as snow, and His eyes like a flame of fire*
Albino Animals - Albino and white mammals and birds
Albino frogs
Albino Tiger Barb
Albino Corydorus paleatus
Pale Riders Who Wear Black Hats - Wired News article on albinism in cinema
[1] - Albino portraits by Pieter Hugo