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June 24

albino squirrel Photo Credit: Kirstin Fearnley. All rights reserved.

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Albinism

An abino is a person or animal with milky skin, white or colorless hair, and pink, purple, light blue, or (in humans) pale eyes caused by a lack of skin pigmentation called melanin. A partial albino lacks melanin in some features, but has it in others (such as the dark markings or "points" on a Siamese cat's coat).

Albinism is a rare genetic disorder that can affect all classes of vertebrates, including humans. Carried in a recessive gene, it is caused by a mutation of the enzyme that regulates melanin production, tyrosinase. Among humans, it affects one in 17,000.

Albinos are particularly sensitive to sun damage and sunburn because melanin absorbs radiation from UV rays. It also contributes to the development of the optical system, so its absence can cause some albinos to suffer from eyesight problems. In addition to problems caused by the body's response to a lack of pigmentation, albinos also can suffer from outside problems, such as difficulty hiding from predators, discrimination, and persecution.

Not all animals with white coats are full or partial albinos, however, nearly all white-coated animals with pink or pale blue eyes are. Dark-eyed animals with white coats are not usually considered albinos.

Learn more about skin pigmentation, genetics, and camouflage with these resources from Science NetLinks:


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