Albinism refers to a group of rare inherited disorders that are present from birth. Albinism affects the amount of pigment found in the skin, hair, and eyes. People with albinism usually have little to no pigment in their eyes, skin, and hair, but the degree of pigment loss can be quite variable. There are three types of Albinism:
Type 1—persons have complete absence of pigment. Their skin, hair, and eyes lack all pigment from birth, and they do not develop freckles or moles at any time during their lifetimes. This group is divided into several subtypes depending on associated characteristics.
Type 2—persons have decreased pigment, but may still have freckles and moles. This form of albinism is more common among persons of African descent and may be associated with such minimal pigment loss that it is evident only by comparison with other non-affected family members.
Type 3, ocular albinism—is characterized by loss of eye pigment and poor vision without any changes in skin or hair.
Both Type 1 and Type 2 albinism are usually associated with visual problems including nystagmus (abnormal jumping movements of the eyes) and decreased visual acuity, which is frequently not fully improved with glasses or contact lenses.
Albinism occurs as a result of altered genes, which are in most cases inherited from parents. Albinism appears in different forms and may be inherited by one of several modes: autosomal recessive, autosomal dominant, or X-linked.
Autosomal recessive inheritance accounts for the vast majority of cases. This means that while both parents carry one copy of an abnormal gene, they have no symptoms or signs of albinism. Children become affected only if they inherit one affected gene from each parent. In this form of inheritance, each child has a one-in-four chance of inheriting the condition. The abnormal gene reduces (or completely eliminates) the body’s ability to make a pigment called melanin. There are several dozen different genetic subtypes of albinism which affect melanin production. Individuals can have full or partial absence of this pigment which will affect the color of eyes, hair, and skin.
A risk factor is something that increases your chances of getting a disease or condition. Albinism is a hereditary disorder. Therefore, people at risk of inheriting albinism are:
The symptoms of albinism depend on the specific type of albinism one has. Some types affect the skin, hair, and eyes. Other types affect only the eyes or only the skin.
Symptoms may include:
In many types of albinism, the disorder can be diagnosed by observation of major or total absence of pigmentation of the hair, skin, and eyes. If needed, chemical testing of hair can provide an easy confirmation of the diagnosis. Because most types of albinism affect the eyes, certain eye tests (including an electroretinogram) are used to help confirm the diagnosis. For some types of albinism, DNA genetic testing can also be used to confirm the diagnosis.
While albinism is always apparent at birth, it may be so mild that affected persons are unaware of their diagnosis unless abnormal eye movements or vision develop.
There is no cure for albinism. Treatment is aimed at preventing or limiting symptoms. In some cases, specific treatment for certain symptoms is needed.
Preventive treatment may include:
Specific treatment of symptoms for albinism may include:
These treatments may be of special importance in Africa where the World Health Organization estimates that thousands of affected individuals live without access to important medical and preventive care.
Studies in mice with genetic forms of albinism suggest that gene transfer may prevent visual disturbances. Whether these results may someday be applied to people with ocular albinism remains to be seen.
RESOURCES:
National Library of Medicine
http://www.nlm.nih.gov
National Organization for Albinism and Hypopigmentation (NOAH)
http://www.albinism.org
CANADIAN RESOURCES:
Canadian Dermatology Association
http://www.dermatology.ca/patients_public
Canadian Ophthalmological Society
http://www.eyesite.ca/
References:
Hong ES, Zeeb H, Repacholi MH. Albinism in Africa as a public health issue. BMC Public Health . 2006 Aug 17;6:212.
The Merck Manual of Medical Information . Simon and Schuster, Inc.; 2000.
National Library of Medicine website. Available at: http://www.nlm.nih.gov .
National Organization for Albinism and Hypopigmentation (NOAH) website. Available at: http://www.albinism.org .
Perry PK, Silverberg NB. Cutaneous malignancy in albinism. Cutis . 2001 May;67(5):427-30.
Rees JL. Genetics of hair and skin color. Annu Rev Genet . 2003;37:67-90.
Surace EM, Domenici L, Cortese K, Cotugno G, Di Vicino U, Venturi C, et al. Amelioration of both functional and morphological abnormalities in the retina of a mouse model of ocular albinism following AAV-mediated gene transfer. Mol Ther . 2005 Oct;12(4):652-8.
Last reviewed November 2008 by Rosalyn Carson-DeWitt, MD
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