РефератыИностранный языкAlAlbinism Essay Research Paper The word albinism

Albinism Essay Research Paper The word albinism

Albinism Essay, Research Paper


The word albinism refers to a group of inherited conditions. People with


albinism have little or no pigment in their eyes, skin, or hair. Recently a test


has been developed to identify carriers of the gene for ty-neg albinism and for


other types in which the tyrosianase enzyme does not function. The test uses a


sample of blood to identify the gene for the tryrosinase enzymes by its code in


DNA. The above test does not apply to to one type of albinism, called X-linked


ocular albinism. For X-linked inheritance, the gene for albinism is located on


an X chromosome. Females have two X chromosomes, while males only have one X and


one Y chromosome. This X-linked albinism accurs exclusively in males. The gene


is passed from mothers who carry it to their sons. The mothers have subtle eye


changes which an ophthalmogist could identigy, but mothers usually have normal


vision. For each son born to a mother who carries the gene, there is one in two


chance of having X-linked ocular albinism. The description is a hereditary


deficiency pigmentation. This could involve the entire body or part of the body.


This is believed to be caused by an enzyme deficiency involving the metabolism


of melanin during prenatal development. This can be inherited by an dominant or


recessive trait. In complete albinism, there is lack of pigmentation in skin and


hair, as well as in retinal and iris tissue; in incomplete albinism, skin and


hair may vary from pale to normal; in ocular albinism, function may vary from


norma to impaired. Impairments may involve the retina and iris. If a person has


albinism then they usually have somewhere between 20/70 and 20/200 visual.


Ty-Neg albinism or also called type 1A results from a genetic defect in an


enzyme called tyrosinase. Tyrosinase helps the body to change the amino acid


tyrosine into pigment. An amino acid is a building block of protien. Albinism is


passed from parent to their kid through genes. For nearly all types of albinism


both parent must carry an albinis

m gene to have a child with albinism. Parents


may have normal pigmentation but still carry the gene. When both parents carry


the gene, there is a one in four chance at each pregnancy that the baby will be


born with albinism. This type of inheritance is called autosomal recessive


inheritance. Eye conditions common in albinism include: ? Nystagmus, irregular


rapid eye movement of the eyes back and forth. ? Strabismus, muscle imbalance


of the eyes either crossed or lazy eye. ? Sensitive to bright light and glare.


? People with albinism may be either far-sighted or near-sighted, and often


have astigmatism. These eye problems result from abnormal development of the eye


because of lack of pigment. Various optical aids are helpful to people with


albinism, and the choice of an optical aid depends on how a person uses his or


her eyes in a job. Some people do well with bifocals which have a strong reading


lens. Others use hand-held magnifiers or special small telescopes. Others use


contact lens. Some use bioptics which have small telescopes mounted on or in or


behind the regular lenses. In the United States, people with albinism live


normal life spans and have the same types of general medical problems as the


rest of the people would. Yet those who live in tropical countries and do not


use proper skin protection may develop life-threatening skin cancer. If they use


appropriate skin protection, such as sunscreen rated 20 or higher, and opaque


clothing, people with albinism can enjoy outdoor activities. People with


albinism are at risk of isolation, because the condition and they are often


misunderstood. Social stigmatization can occur, especially among communities of


color. We should all help by including them in all activities and not


discriminate against them. In conclusion the facts on people with albinism are


that one in 17,000 people has some type of albinism. Albinism effects people


from all races. Most children with albinism are born to parents who have normal


hair and eye color for their backgrounds.

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