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Everything you need to know about albinism | by heidi

 



Albinism refers to a range of disorders that result from a reduction in or absence of the pigment melanin. These vary in severity, but they often cause white skin, light hair, and vision problems.


Albinism can affect anyone, but its prevalence varies by region.


In sub-Saharan Africa, albinism affects 1 in every 2,000 to 5,000Trusted Source people. Among some groups, the rate is as high as 1 in 1,000. In Europe and the United States, it is closer to 1 in 17,000 to 20,000.


Albinism affects the sexes evenly, and all ethnic groups are susceptible.


Below are some key points about albinism. More details follow in the main article.


Albinism is a genetic condition.

It primarily affects the hair, eyes, skin, and vision.

There is no cure for albinism, but some symptoms are treatable.

What is albinism?

Albinism is an inherited disease characterized by a substantially lower rateTrusted Source of melanin production.


Melanin is the pigment responsible for the color of the skin, hair, and eyes.


People with albinism often have lighter colored skin and hair than the other members of their family or ethnic group. Vision problems are also common.


Melanin normally protects the skin from damage due to UV radiation exposure, so people with albinism are more sensitive to sun exposure. They also have an increased risk of developing skin cancer as early as the teenage years.



Types

Albinism has two main types: ocular albinism (OA), which primarily affects the eyes, and oculocutaneous albinism (OCA), which affects the skin, hair, and eyes.


Doctors further subdivide OCA into a number of subgroups depending on the specific genes it affects.



OCA type 1: Individuals tend to have milky skin, white hair, and blue eyes. With age, some individuals’ skin and hair may darken.

OCA type 2: Less severe than type 1, this occurs most often in sub-Saharan Africans, African Americans, and some Native American communities.

OCA type 3: Vision problems are usually milder in type 3 than in other types. This type mostly affects Black South Africans.

OCA type 4: This type is most common among East Asian populations. It presents similarly to type 2.

X-linked ocular albinism: A genetic mutation in the X chromosome causes X-linked ocular albinism, which mainly affects males. Vision problems are present, but eye, hair, and skin color are generally within the normal range.

Chediak-Higashi syndrome: This is a very rare form of albinism resulting from a mutation in the CHS1 gene. The symptoms may resemble those of oculocutaneous albinism, but a person’s hair can appear silvery, and their skin can look slightly gray. The white blood cells can have defects, making the person more prone to infections.

Symptoms

The main symptoms of albinism affect the vision and the color of the skin, hair, and eyes.


Skin


An individual’s skin may burn easily in the sun, and it does not usually tan. After sun exposure, some people with albinism might develop:


freckles

moles, which are usually pink in color due to the reduced quantities of pigment

lentigines, which are large freckle-like spots

There is also a higher risk of skin cancer. People with albinism should use sunscreen with an SPF of at least 20 and report any new moles or other skin changes to a doctor.


Hair

In people with albinism, hair color can range from white to brown. Those of African or Asian descent tend to have yellow, brown, or reddish hair.


As the individual ages, their hair color may slowly darken.


Eye color

Eye color may also change with age and can vary from very light blue to brown.


Low levels of melanin in the iris mean that the eyes can appear slightly translucent and, in a certain light, look red or pink as the light reflects off the retina at the back of the eye.


The lack of pigment prevents the iris from fully blocking sunlight, so the person is sensitive to light. Doctors call this photosensitivity.


Vision


Nystagmus: The eyes move rapidly and uncontrollably back and forth.

Strabismus: The eyes do not align.

Amblyopia: This is the medical name for a lazy eye.

Myopia or hypermetropia: The person may have extreme nearsightedness or farsightedness.

Photophobia: The eyes are particularly sensitive to light.

Optic nerve hypoplasia: Visual impairment happens because an individual’s optic nerve is underdeveloped.

Optic nerve misrouting: Nerve signals from the retina to the brain follow unusual nerve routes.

Astigmatism: An abnormal inflexibility of the front surface of the eye or lens results in blurred vision.

Strategies that may help include:


attaching special telescopic lenses to glasses

using a large computer screen or high contrast print material

installing software that converts text to speech

using a brightly colored ball when playing games

Causes

Specialized cells in the skin, hair, and eyes called melanocytes produce melanin. If there is a change in one of these genes, it can cause albinism. Experts estimate that 1 in 70 peopleTrusted Source carry these genes.


Most commonly, the mutations interfere with an enzyme called tyrosinase. This enzyme breaks down the amino acid tyrosine and creates melanin.


Depending on the specific mutation, melanin production either slows down or stops entirely.



Is it genetic?

Yes, albinism is genetic. Most types of albinism have what doctors call an autosomal recessive inheritance pattern. The exception is X-linked ocular albinism, which has an X-linked inheritance pattern.


Autosomal recessive inheritance

With autosomal recessive inheritance, an individual must receive mutated copies of a gene from both the mother and father to develop albinism. The parent who carries the gene often does not show symptoms.



There is a 1 in 2 chance that the child will become a carrier, meaning that they carry the gene but have no symptoms.


X-linked inheritance

X-linked recessive conditions mainly affect males. The reason for this is that females carry two X chromosomes, so if one gene is damaged, the other can often make up the shortfall. However, females can still carry and pass on the affected gene.


Males, however, have one X and one Y chromosome. As a result, any albino mutations in their singular X chromosome will generate the condition.


If the mother has an X-linked mutation, each daughter has a 1 in 2 chance of becoming a carrier, and each son has a 1 in 2 chance of developing albinism.



Diagnosis


a physical exam

a discussion about skin and hair pigmentation changes

the examination of the eyes by an ophthalmologist, a specialist eye doctor

a comparison of the individual’s coloration with that of biological family members

Other diseases can also cause changes in pigmentation, but they do not cause vision changes. If pigment and vision changes are both present, doctors consider albinism a likely diagnosis.


Genetic testing is the most reliable way to diagnose albinism. However, it is expensive, and doctors do not consider it necessary in families with a history of albinism.



Treatment

Albinism is a lifelong genetic condition with no cure. Therefore, treatment focuses on minimizing the symptoms and watching for skin changes.



prescription glasses

dark glasses to protect the eyes from the sun

regular eye exams

Surgery on the optical muscles can sometimes minimize the “shaking” that occurs in nystagmus. Procedures to minimize strabismus can make it less noticeable, but surgery does not improve the vision. The level of success in reducing symptoms varies among individuals.


People should watch their skin carefully for any changes and use sunscreen for protection.


Complications


Visual deficits can also limit an individual’s work opportunities and their ability to obtain a driver’s license. Additionally, a person may have reading difficulties that lead to educational delays.




In 2015, the United Nations called for “urgency” in taking measures to prevent attacks on people with albinism.

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