Tuesday, 24 November 2015

#66 Albinism (English)

Albinism


Otherwise known as achromia, achromasia, or achromatosis, albinism is a genetic condition characterized by a deficit in the production in melanin resulting in the partial or complete absence of pigment in the skin, hair and eyes. This hereditary disease can be found in humans, mammals, birds, fish, reptiles and amphibians. Despite the fact that albinism is a hereditary condition, in most cases, there's no family history of it. People with albinism often have vision problems and are vulnerable to sunburns and skin cancers if they do not protect themselves well enough. According to The National Organization for Albinism and Hypopigmentation, one in every 17,000 people in the United States has some type of albinism.

Oculocutaneous albinism is used to refer to people with little or no pigmentation in their eyes, skin and hair. Little or no pigmentation in the eyes alone is known as ocular albinism. An individual with complete absence of melanin is called an albino. One with only a small amount of melanin is described as albinoid. People with albinism are very pale with fair hair and very light eyes. In some cases, the eyes appear red or purple as the iris actually has so little color that  blood vessels inside of the eye show through. Hence why the main test for albinism is an eye test.

A person with albinism is generally as healthy as the rest of the population. However, problems with vision and skin are particularly common. Vision problems result from abnormal development of the retina and patterns of nerve connections between the eye and the brain. The lack of pigment in the eyes results in problems with eyesight leading to discomfort in bright light. Concerning the skin, the lack of melanin, which helps protect the skin from UV radiation, means that their skin can burn more easily. Precautions, such as applying lots pf suncream and staying covered, need to be take to avoid damage to the skin caused by the sun.

Albinism is caused when a person inherits one or more defective genes that cause them to be unable to produce the normal amounts of a melanin. Melanin is a dark brown to black pigment occurring in the hair, skin, and iris of the eye in people and animals. It is responsible for the tanning of skin when exposed to sunlight.

Researchers have identified several genes that result in albinism. The genes are located on "autosomal" chromosomes - chromosomes that contain genes for general body characteristics. Genes carry the information that makes you an individual. Albinism is a "recessive trait" - a person without albinism can carry the albinism trait. Both parents must carry a defective gene to have a child with albinism. When neither parent has albinism but both carry the defective gene, there is a 25% chance that the baby will be born with albinism.

Individuals with this condition are often outcasted and misunderstood by society. They can be the center of ridicule, fear and even violence.
 
McA

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