The FACTS About Albinism

Sat, 20 May 2006 14:43:01 GMT

I just thought I'd set a few things straight about albinism (albinos), seeing as I am one, and am fed up with people believing the rumours that are often found 'floating' around

MYTHS
The following statements are NOT TRUE, according to current knowledge in the field:

* Persons with albinism always have red eyes.
* Persons with albinism are totally blind.
* Albinism is contagious.
* Persons with albinism are the result of evil spirits or wrongdoing.
* Persons with albinism are retarded or deaf.
* Albinism results from inbreeding or the mixture of two races.
* Persons with albinism have magical powers.

DEFINITION OF ALBINISM
Albinism refers to a group of inherited conditions. People with albinism have absent or reduced pigment in their eyes, skin or hair. They have inherited genes that do not make the usual amounts of a pigment called melanin which is essential for the full development of the retina. Lack of melanin in development of the retina is the primary cause of visual impairment in albinism. In the USA it is estimated that one person in 17,000 has some type of albinism.
There are two major categories of albinism (overlap of these categories often occurs):

Ocular Albinism (OA) is divided into two types according to the inheritance pattern:
autosomal recessive OA occurring equally in males and females, and X-linked OA with symptoms occurring primarily in males. In the X-linked cases, mothers carry the gene and pass it to their sons. Although the mothers usually have normal vision, they have subtle eye changes that can be identified by an ophthalmologist. If a woman does carry the gene, with each pregnancy there is a one in two chance of having a son with X-linked ocular albinism. For specific information, families should seek the advice of a qualified genetic counselor.

Oculocutaneous Albinism (OCA, involves the lack of pigment in the hair, skin and eyes. Each parent must carry the gene for this form which follows an autosomal recessive inheritance pattern, meaning there is a one in four chance at each pregnancy that the baby will be born with albinism. Within OCA there are two primary types of albinism.
Type 1 (formerly known as Tyrosinase Negative) involves the complete lack of pigment. These children have white skin and hair and moderate to severe visual impairment. Children with
Type 2 (formerly known as Tyrosinase Positive) have various amounts of pigmentation, yellow or blonde hair and usually less severe visual impairment.

Secondary OCA
The appearance of albinism may indicate the presence of other rare conditions that require special management. Hermansky-Pudlak Syndrome (HPS) involves a platelet defect that results in susceptibility to bleeding and bruising. Aspirin and aspirin-like drugs should be avoided, as they may convert a mild bleeding disorder into a severe one. HPS can be identified by a specialized test involving electron microscopy of the platelets. Chediak-Higashi Syndrome is associated with a white blood cell problem leading to a susceptibility to bacterial infections. Prior to a surgical procedure for persons with these rare forms of albinism, specific tests for bleeding dysfunction and white blood cell abnormalities should be performed.

CHARACTERISTICS

* Low Vision (visual acuity between 20/50 and 20/800)
* Sensitivity to bright light and glare (photophobia)
* Rhythmic, involuntary eye movements (nystagmus)
* Absent or decreased pigment in the skin and eye and sensitivity to sunburn (ultraviolet light) that could lead to skin cancers or cataracts in later life
* "Slowness to see" in infancy
* Farsighted, nearsighted, often with astigmatism
* Underdevelopment of the central retina (foveal hypoplasia)
* Decreased pigment in the retina (blonde fundus)
* Inability of the eyes to work together (absence of stereo vision)
* Misrouting of the nerve pathways from the retina to the brain
* Light colored eyes ranging from lavender to hazel, with the majority being blue
* Strabismus, with both vertical and horizontal deviations

For more information on albinism, please go to Albinism.org.

Meaghan

The FACTS About Albinism