Albinism

By Colleen and Shannon

What is Albinism?

Definition: Albinism is an inherited condition present at birth, characterized by a lack of pigment that normally gives color to the skin, hair, and eyes. Many types of albinism exist, all of which involve lack of pigment in varying degrees. The condition, which is found in all races, may be accompanied by eye problems and may lead to skin cancer later in life (The Free Dictionary ). This in other words means having blond to white colored hair, very pale skin, and but often have normal colored eyes. There are 1 in 17,000 people in the United States with some type of albinism. Worldwide, there are 1 in 20,000 people with albinism.

Types of Albinism

There are 4 main types of albinism:
  1. Oculocutaneous albinism - all pigmentation is absent
  2. X-Linked albinism - eye color is altered and vision problems but no difference in skin color
  3. Chediak-Higashi albinism - immune system complications and white blood cell abnormalities
  4. Hermansky-Pudlak albinism - lung disease and bleeding problems along with albinism

Most people get the type of albinism where they have pale skin, hair and eyes. The less common types of albinism are the ones where you have many complications, such as in Hermansky-Pudlak albinism.

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Genetics Behind Albinism

Most people inherit albinism, because it is normally a recessive trait. Some people have mutated genes and therefore do not inherit it, but this is not very common. Oculocutaneous albinism is the most common inherited type.

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Vision Problems

Albinism also causes many types of vision problems. Some types are:
  • Nystagmus: regular horizontal back and forth movement of the eyes
  • Strabismus: muscle imbalance of the eyes, “crossed eyes” (esotropia), “lazy eye” or an eye that deviates out (exotropia)
  • Photophobia: sensitivity to bright light and glare
  • People with albinism may be either far-sighted or near-sighted and usually have astigmatism
  • Foveal hypoplasia: the retina, the surface inside the eye that receives light, does not develop normally before birth and in infancy
  • Optic nerve misrouting: the nerve signals from the retina to the brain do not follow the usual nerve routes
  • The iris, the colored area in the center of the eye, has little to no pigment to screen out stray light coming into the eye. (Light normally enters the eye only through the pupil, the dark opening in the center of the iris, but in albinism light can pass through the iris as well.)

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Works Cited

http://www.albinism.org/publications/what_is_albinism.html
http://medical-dictionary.thefreedictionary.com/Albinism+in+humans