Monday, August 24, 2009

Albinism

Albinism is an inherited condition that affects the production of the pigment, melanin. People or other animals with albinism have little or no pigment in their eyes, skin, and hair. A cell called melanocyte produces the pigment; these cells are present in people with albinism, but a genetic mutation interferes with the production or distribution of melanin.

We recognize people with albinism by their snow white hair, light skin, and pale pinkish blue eyes. In some cultures, particularly in East Africa, albinistic people are treated as outcasts and worse. Our neighbors next door have two children with albinism. Despite the stigma that popular culture attaches to this condition, these kids have the most fun outdoors of any kids in our neighborhood. They swim, kayak, bike, and otherwise play outside all summer long. Far from thinking of their condition as a disease or disorder, their appearance has no bearing on their outlook on life, as far as we can tell.

There are no major health concerns associated with albinism, except for apparently an increased risk of skin cancer and some potential vision problems. The melanocytes produce something akin to umbrellas in our skin, protecting us from ultraviolet radiation. Lacking these internal "umbrellas" albinistic people require extra care out in the sun. We all should take more care in the sun.

My nephew-in-law Sid sent the following photos that he took of an albinistic cobra in southern India. The patterns are stunning on a cobra anyway and this one is especially beautiful. Note the pink eyes. The redness comes from light entering the pupil and reflecting off the blood vessels in the retina. Typically the pupil appears black because pigment molecules in the retina absorb light entering the eye, preventing it from reflecting back out.



There is some thought that animals with albinism may be more visible to predators or prey, and hence have a shorter lifespan. I was not able to confirm that in a quick online search. Some predators may not notice an albinistic prey because their search image may be for a brown animal not a white animal. Many different animals can produce albinistic offspring, but just seeing an animal that is white does not mean that it has albinism. Some other mutations can cause patches of hair or skin to lack pigment. Regardless, they are striking, and are often treated differently.

Our neighbor kids have shown us that their "differences" are quite normal!

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