Albinism
(Hypopigmentation; Oculocutaneous Albinism; Ocular Albinism)
Definition
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.
Causes
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.
Risk Factors
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:
- Children of parents who have albinism
- Children of parents who do not have albinism, but carry the altered genes that cause this disorder
- A positive family history for albinism in a sibling or other relative
- Puerto Rican ancestry (this significantly increases the risk of an otherwise rare form of albinism known as Hermansky-Pudlak syndrome)
Symptoms
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.
Eye Symptom—Strabismus
Symptoms may include:
-
Eye problems, such as:
- Strabismus or crossed or wandering eye
- Poor vision (which usually cannot be fully corrected with glasses or contacts)
- In some cases, functional blindness
- Nystagmus or irregular, rapid eye movement.
- Amblyopia or “lazy” eye.
- Photophobia–sensitivity to bright lights or glare
-
Skin problems, including:
- Little or no pigmentation (resulting in extremely light or white skin)
- Patches of low pigmentation (resulting in patches of extremely light or white skin)
- Extreme sensitivity to sunburn
- Very high susceptibility to skin cancer
-
Hair problems, including:
- White hair
- Portions of the hair (often the forelock) being white
-
Certain rare types of albinism, such as Hermansky-Pudlak syndrome, can cause other symptoms, including:
- Bleeding disorders
- Lung disease
- Bowel disease
- Infections
- Hearing loss
- Nervous system disorders
- The common forms, Type 1 and 2 albinism are not associated with these more serious symptoms.
Diagnosis
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.
Treatment
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
Preventive treatment may include:
-
Protect the skin:
- Sunburn and skin cancer risks can be reduced by avoiding the sun as much as possible
- Wear sunscreen with high SPF,15 or higher
- Cover as much skin as possible with clothing when exposed to the sun
-
Protect the eyes:
- Wear sunglasses with UV protection whenever exposed to the sun
- Sunglasses (UV protected) may relieve photophobia
Specific Treatment of Symptoms
Specific treatment of symptoms for albinism may include:
-
For eyes:
- Glasses, contacts, and/or optical aids to help improve vision
- Surgery to correct certain eye problems, including crossed eyes or “lazy” eye
- Visual aids (in the classroom) to help children with albinism
-
For skin:
- Surgery to treat and/or remove skin cancer , if necessary
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.
Prognosis
- Patients with the most common forms of Type 1 and Type 2 albinism and ocular albinism have a normal lifespan.
- An increased risk of skin cancer exists; however, with careful ongoing surveillance this risk can be minimized. Since melanoma skin cancer may occur without characteristic pigmentation, a high level of dermatologic vigilance is required to ensure early diagnosis.
- Affected patients usually have unaffected children unless married to another individual with albinism.
- Albinism does not cause a delay in development or mental retardation.
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
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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