Albinism

=Albinism=

From the aptly named geneticdisordersproject.wikispace.com


 * Albinism** is a genetic disorder that is inherited on a recessive allele. Albinism causes the body to produce an unusual amount of the pigment melanin. The resulting organism lacks normal coloring, although will not always be colorless. Organisms with Albinism are commonly associated with red or violet eyes, although normal colors of hazel, brown, and blue are still commonly present. Skin or hair color is not always colorless in organisms of albinism, though such is not always so; many afflicted with the dis[[image:Albinisitic_man_portrait.jpg width="190" height="216" align="right" caption="Fig. 1 - An African boy with Albinism." link="http://en.wikipedia.org/wiki/Image:Albinisitic_man_portrait.jpg"]]order have fair or pale coloring. Vision problems are a direct result of the lack of eye pigment caused by albinism.

Inheritance
There are four primary forms of albinism, each inherited in a different way. The most common, oculocutaneous albinism (OCA) type 2 occurs once in about every 15,000 people. It is inherited on chromosome 15, and is an autosomal recessive genetic trait. The next most common, OCA type 1, occurs once in every 40,000 cases, and is inherited on chromosome 11; also as an autosomal recessive trait. The third common type of pigmentary albinism is OCA type 3 and is the most rare of the three, occurring once in every 50,000 cases. OCA 3 is caused by a gene on chromosome 9 and is also autosomal recessive. Ocular (of the eye) albinism is a sex linked trait, and is recessive.

Symptoms
A common symptom associated with albinism is the absences of color pigment in the skin, leading it to be pale or white (see Figure 1). However in many organisms, including humans, yellowish colors will be present, because the gene that produces that pigment will not be effected by albinism. Because many organisms with albinism lack (or do not have enough of) the dark pigment melanin, which helps protect the body from ultraviolet radiation, so they sunburn easily. Organisms with albinism also have a higher rate of skin cancer for this same reason.

Albinism also can have direct effects on the eye of the afflicted organism. Oftentimes the eyes will appear to be red or pinkish due to the blood vessels underneath being visible. Red eyes are most common in smaller animals (see Figure 2); the human eye is large enough where there is enough pigment that is not affected by albinism to render the eye pale blue or opaque. Organisms with albinism are also highly susceptible to diseases of the eye including, **Strabisums** (lazy eye), **Optic nerve hypoplasia** (under development of the optic nerve), and **Nystagums** (irregular movement of the eye). Albino creatures often have impaired vision, and are photosensitive due to the lack of protective eye pigment.

Diagnosis and Treatment
Diagnosis of albinism ranges from very simple to extremely difficult. In many cases, albinism can be distinguished by examining the organism's skin or pelt. In some cases the effect of albinism is slight, and a genetic screening or chemical test of the organism's hair is required to perform a diagnosis. Several cases of ocular albinism are so slight that they can only be diagnosed with a complete examination of the retina.

Albinism is not a disorder that can be cured in the conventional sense, but rather several things may be done to mitigate the symptoms. They are several surgical options to correct secondary occular disorders that result from albinism, such as the aforementioned Strabisums or Nystagums. Other than that, there are no ways to correct the lack of pigment. Shaded glasses and bifocals are often used to improve and protect the vision of those with occular albinism. Sunscreen is key in protecting albinic individuals from sun-induced skin cancer. Wide-brim hats and tinted windows in cars are also used to the same effect.

Prognosis
A common misconception is that albinic organisms have a reduced lifespan. This is untrue; although organisms with albinism do have a higher rate of skin cancer due to pigment deficiencies. Albinic organisms are thought to go blind halfway through life; this too is untrue, although it stems from the fact most albinic organisms have weakened eyesight. People with albinism will have a full lifespan and are regular members of society.

Additional Information

 * There is a common cultural misconception of supernatural properties being associated with albinism. In Zimbabwe it is believed that sexual intercourse with an albino will cure one of HIV. This has led to the rape of many Zimbabwean women with albinism.
 * The idea of an "evil albino" is a common archetype in fiction. This is seen in H.G. Wells's //The Invisible Man,// in where the villain is albinic, and //The DiVinci Code// where the monk Silas is an albino (see Figure 3).
 * Albinic whales served as the inspiration behind the titular whale in //Moby-Dick.//
 * Approximately 1 in 17,000 people have some type of albinism, and 1 person in 70 is a carrier of an albinic gene.

**Notes: •**This web page complies with the Fair Use guidelines •Each figure has a link to the picture from __Wikipedia, The Free Encyclopedia__. •All pictures taken from http://en.wikipedia.org/

"Albinism." __Wikipedia, The Free Encyclopedia__. 2 April, 2008. 2 April, 2008 <[|http://en.wikipedia.org/wiki/Albinism>.]

Kugler, Mary, R.N. "Albinism." __About.Com: Rare Diseases__. 27 January, 2006. 2 April, 2008. 

Turkington, Carol A. "Albinism." __Health A to Z.__ 14 August, 2006. The Gale Group. 2 April, 2008. 

King, Richard A., Gail C. Summers, James W. Haefemeyer, and Bonnie S. Leroy. "Facts About Albinsim." __International Albinism Center__. 29 December, 2004. University of Minnesota. 4 April, 2008. <[|http://albinism.med.umn.edu/facts.htm>.]

=Comments=

I didn't know that it can be difficult to diagnosis Albinism. Great information, but a few spelling errors. The first picture is quite interesting!

Your page has a lot of useful information. Some things I read were very interesting and that I never knew. Over all nice job! AM and VR

Nice work! Your website looks great and very organized. Yeah, that is interesting that in books with people with Albinism that they have to "evil" roles. I find it sad that woman in Zimbabwe are being raped to cure HIV, thats not right! I like your pictures, they go very well with your website also!~Turner's Syndrome (SL&KT)

Hey, great information!!! We changed the spelling of "recessive" on page. The incorrect spelling was repeated and we changed it where ever we saw it. Good Job. PR & EN

This comment is from your teacher - I found many spelling errors - please look your page over and do a spell check. Otherwise, it looks great!

 We had no idea that it was so hard to diagnosis! Awesome Page!!! KF & LF

Hey just fixed some spelling stuff. -Marfans