- What is albinism
- Complications of albinism
- Types of albinism
- Albinism facts
- Albinism genetics
- What causes albinism
- Prevention of albinism
- Albinism symptoms
- Albinism diagnosis
- Albinism treatment
What is albinism
Albinism is a group of genetic conditions where people are born without the usual pigment (melanin) in the skin, hair and eyes. Melanin also plays a role in the development of certain optical nerves, so all forms of albinism cause problems with the development and function of the eyes.
So most people with albinism have very pale skin, hair, and eyes. Albinism symptoms can include light skin or changes in skin color; very white to brown hair; very light blue to brown eye color that may appear red in some light and may change with age; sensitivity to sun exposure; and increased risk of developing skin cancer 1). Albinism is caused by mutations in one of several genes, and most types are inherited in an autosomal recessive manner 2). Although there’s no cure, people with the disorder can take steps to improve vision and avoid too much sun exposure 3). Albinism can affect people of all races, and there are different kinds of albinism.
The genes for albinism are passed down from both parents, who may not be directly affected by it themselves. However, there is no simple test to determine whether a person carries a gene for albinism.
In the United States, most people with albinism live normal life spans and have the same types of general medical problems as the rest of the population. The lives of people with Hermansky-Pudlak Syndrome can be shortened by lung disease or other medical problems.
In tropical countries, people with albinism who do not have access to adequate skin protection may develop life-threatening skin cancers. If they use appropriate skin protection, such as broad spectrum sunscreens rated SPF 30 or higher and opaque clothing, people with albinism can enjoy outdoor activities even in summer.
People with albinism are just like anyone else, with the same lifespan and ability to reach their goals. But living with any medical condition can be difficult. People with albinism can also suffer from discrimination and social stigmatization. People with albinism are at risk of isolation because the condition is often misunderstood. Good support for all involved can help deal with it. Because the social scene can be more about fitting in than standing out, teens with albinism may face bullying or prejudice. Voicing any frustration or sadness to a family member or friend who understands can help. So can talking to a counselor or therapist to get ideas on coping with the challenges that come up during the teen years. Families and schools must also make an effort to include children with albinism in group activities. Contact with others with albinism or who have albinism in their families or communities is most helpful. National Organization for Albinism and Hypopigmentation 4) can provide the names of contacts in many regions of the country.
It is important for people with albinism to protect their skin and eyes from the sun, and have their eyes checked regularly.
Impact on eye development
Regardless of which gene mutation is present, vision impairment is a key feature of all types of albinism. These impairments are caused by irregular development of the optic nerve pathways from the eye to the brain and from abnormal development of the retina.
Except for eye problems, most people with albinism are just as healthy as anyone else. In very rare cases a person’s albinism is part of another condition that involves other health problems in addition to albinism. People with these types of albinism can have such health complications as bleeding, lung, bowel, and immune system problems.
Complications of albinism
Complications of albinism include skin disorders as well as social and emotional challenges.
One of the most serious complications associated with albinism is the risk of sunburn and skin cancer.
Social and emotional factors
The reactions of other people to those with albinism can often have a negative impact on people with the condition.
- Children with albinism may experience name-calling, teasing or questions regarding their appearance, eyewear or visual aid devices.
- Many people with albinism find the word “albino” hurtful because they’re being labeled simply on the basis of looks rather than being thought of as individuals.
- People with albinism usually look very different from members of their own families or ethnic groups, so they may feel like outsiders or be treated like outsiders.
All of these factors may contribute to social isolation, poor self-esteem and stress.
Types of albinism
Different types of albinism can have different patterns of inheritance, depending on the genetic cause of the condition. Oculocutaneous albinism involves the eyes, hair and skin. Ocular albinism, which is much less common, involves primarily the eyes, while skin and hair may appear similar or slightly lighter than that of other family members. Mutations in several different genes, on different chromosomes, can cause different types of albinism.
There are two main types of albinism:
Ocular albinism (OA1), in which the eyes are affected, but the color of their hair and skin is fairly normal. Ocular albinism is inherited in an X-linked pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. In males (who have only one X chromosome and one Y), one altered copy of the causative gene in each cell is sufficient to cause the characteristic features of ocular albinism, because males do not have another X chromosome with a working copy of the gene. Because females have two copies of the X chromosome, women with only one copy of a mutation in each cell usually do not experience vision loss or other significant eye abnormalities. They may have mild changes in retinal pigmentation that can be detected during an eye examination.
The cause of X-linked ocular albinism, which occurs almost exclusively in males, is a gene mutation on the X chromosome. People who have ocular albinism have vision problems, but their skin, hair and eye color are generally in the normal range or slightly lighter than that of others in the family. People with ocular albinism usually have blue eyes. In some cases, the iris (the colored part of the eye) has very little color so a person’s eyes might look pink or reddish. This is caused by the blood vessels inside the eye showing through the iris. In some forms of ocular albinism, the hearing nerves hearing may be affected and the person may develop hearing problems or deafness over time.
Oculocutaneous albinism, in which the hair, skin and eyes are all affected. People with oculocutaneous albinism have extremely pale skin and eyes, and white hair. Others with this same type of albinism might have slightly more color in their hair, eyes, or skin. Oculocutaneous albinism is inherited in an autosomal recessive manner. This means that two mutations are necessary for an individual to have oculocutaneous albinism. Individuals normally have two copies of each numbered chromosome and the genes on them – one inherited from the father, the other inherited from the mother. Neither of these gene copies is functional in people with albinism. Each unaffected parent of an individual with an autosomal recessive condition carries one functional copy of the causative gene and one nonfunctional copy. They are referred to as carriers, and do not typically show signs or symptoms of the condition. Both parents must carry a defective oculocutaneous albinism gene to have a child with albinism. When two individuals who are carriers for the same autosomal recessive condition have children, with each pregnancy there is a 25% (1 in 4) risk for the child to have the condition, a 50% (1 in 2) risk for the child to be an unaffected carrier like each of the parents, and a 25% chance for the child to not have the condition and not be a carrier.
Recent research has used DNA analysis, the chemical that encodes genetic information, to arrive at a more precise classification system for albinism. Seven forms of oculocutaneous albinism are now recognized – OCA1, OCA2, OCA3, OCA4, OCA5, OCA6 and OCA7 5). Some are further divided into subtypes:
- Oculocutaneous albinism type 1, or tyrosinase-related albinism, results from a genetic defect in an enzyme called tyrosinase. This enzyme helps the body to change the amino acid, tyrosine, into pigment. (An amino acid is a “building block” of protein.) There are two subtypes of oculocutaneous albinism type 1. In oculocutaneous albinism type 1A, the enzyme is inactive and no melanin is produced, leading to white hair and very light skin. In oculocutaneous albinism type 1B, the enzyme is minimally active and a small amount of melanin is produced, leading to hair that may darken to blond, yellow/orange or even light brown, as well as slightly more pigment in the skin.
- Oculocutaneous albinism type 2, or P gene albinism, results from a genetic defect in the P protein that helps the tyrosinase enzyme to function. People with oculocutaneous albinism type 2 make a minimal amount of melanin pigment and can have hair color ranging from very light blond to brown. Oculocutaneous albinism type 2 is most common in sub-Saharan Africans, African-Americans and Native Americans. The hair may be yellow, auburn, ginger or red, the eyes can be blue-gray or tan, and the skin is white at birth. With sun exposure, the skin may, over time, develop freckles, moles or lentigines.
- Oculocutaneous albinism type 3 is rarely described and results from a genetic defect in TYRP1, a protein related to tyrosinase. People with oculocutaneous albinism type 3 can have substantial pigment. People with oculocutaneous albinism type 3, mainly found in black South Africans, usually have reddish-brown skin, ginger or reddish hair, and hazel or brown eyes.
- Oculocutaneous albinism type 4 results from a genetic defect in the SLC45A2 protein that helps the tyrosinase enzyme to function. People with oculocutaneous albinism type 4 make a minimal amount of melanin pigment similar to people with oculocutaneous albinism type 2. Oculocutaneous albinism type 4 looks similar to type 2 and is most often found in people of East Asian descent.
- Oculocutaneous albinism type 5–7 were recognized in humans in 2012 and 2013. They have reported mutations on three additional causative genes. As gene testing becomes available, and more people with these types of albinism are identified, the complete range of physical manifestations will be recognized, and may overlap with other known types of oculocutaneous albinism. Currently, these types of albinism are considered to be uncommon.
There are also some extremely rare conditions where people have albinism and other health problems. Examples are Hermansky Pudlak syndrome, Chediak Higashi syndrome and Griscelli syndrome. One group of these includes at least ten genes (on different chromosomes) leading to Hermansky-Pudlak Syndrome. In addition to albinism, Hermansky-Pudlak Syndrome is associated with bleeding problems and bruising. Some forms are also associated with lung and bowel disease. Like oculocutaneous albinism, Hermansky-Pudlak Syndrome is inherited in an autosomal recessive manner.
- Hermansky-Pudlak syndrome. Hermansky-Pudlak syndrome is a rare albinism disorder caused by a mutation in one of at least ten different genes. The disorder is much more common in Puerto Rico. People with this disorder have signs and symptoms similar to people with oculocutaneous albinism, but they may also develop lung and bowel diseases, or a bleeding disorder.
- Chediak-Higashi syndrome. Chediak-Higashi syndrome is a rare form of albinism associated with a mutation in the LYST gene. With signs and symptoms similar to oculocutaneous albinism, the hair is usually brown or blond with a silvery sheen, and the skin is usually creamy white to grayish. People with this syndrome have a defect in white blood cells that increases their risk of infections.
Eyesight and Albinism
People with albinism often have trouble with their eyesight. They may wear glasses or contact lenses to help correct problems like nearsightedness, farsightedness, or astigmatism. Others might need eye surgery. Just as there are different degrees of albinism there are also different levels of eye problems for a person who has the condition.
Albinism does not make a person completely blind. Although some people with albinism are “legally blind,” that doesn’t mean they have lost their vision completely. They can still read and study — they just may need larger print or magnifiers to help them.
People with albinism can be very sensitive to light because the iris doesn’t have enough color to shield the retina properly. Wearing sunglasses or tinted contact lenses can help make them more comfortable out in the sun.
Besides giving skin, eyes, and hair their color, melanin helps protect our skin from the sun. It does this by causing skin to tan instead of burn — which is why people with darker skin (more melanin) are less likely to burn than people with lighter skin. So people with albinism can sunburn very easily.
People with light skin are also particularly at risk for skin cancer. So it’s important for people with albinism to use a sunscreen with a high SPF factor at all times and to wear clothing that offers protection from the sun, such as hats, dark-colored clothing, or long pants and long-sleeved shirts.
The genes for oculocutaneous albinism are located on “autosomal” chromosomes. Autosomes are the 22 pairs of chromosomes that contain genes for our general body characteristics, compared to the one pair of sex chromosomes. We normally have two copies of these chromosomes and the many genes on them – one inherited from our father, the other inherited from our mother. For a recessive trait (like most types of albinism) to occur, both of the person’s chromosomes must carry that trait. That means that most types of albinism result from inheriting an albinism trait from both the mother and the father who often have normal pigmentation. In this case, the mother and father are considered to be carriers of the albinism trait because they each carry a recessive gene for the condition but do not manifest the condition themselves. When both parents carry the albinism gene (and neither parent has albinism) 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.
Ocular albinism (OA1) is caused by a change in the GPR143 gene that plays a signaling role that is especially important to pigmentation in the eye. Ocular albinism (OA1) follows a simpler pattern of inheritance because the gene for ocular albinism (OA1) is on the X chromosome. Females have two copies of the X chromosome while males have only one copy (and a Y chromosome that makes them male). To have ocular albinism, a male only needs to inherit one changed copy of the gene for ocular albinism from his carrier mother. Therefore almost all of the people with ocular albinism (OA1) are males. Parents should be suspicious if a female child is said to have ocular albinism. While possible if the mother is a carrier of ocular albinism and the father has ocular albinism, it is extremely rare.
For couples who have not had a child with albinism, there is no simple test to determine whether a person carries a gene for albinism. Researchers have analyzed the DNA of many people with albinism and found the changes that cause albinism, but these changes are not always in exactly the same place, even for a given type of albinism. Moreover, many of the tests do not find all possible changes. Therefore, the tests for the albinism gene may be inconclusive. If parents have had a child with albinism previously, and if that affected child has had a confirmed diagnosis by DNA analysis, there is a way to test in subsequent pregnancies to see if the fetus has albinism. The test uses either amniocentesis (placing a needle into the uterus to draw off fluid) or chorionic villous sampling (CVS). Cells in the fluid are examined to see if they have an albinism gene from each parent.
For specific information and genetic testing, seek the advice of a qualified geneticist or genetic counselor. The American College of Medical Genetics 6) and the National Society of Genetic Counselors 7) maintain a referral list. Those considering prenatal testing should be made aware that people with albinism usually adapt quite well to their disabilities and lead very fulfilling lives.
What causes albinism
Albinism is inherited. It’s not contagious — you can’t “catch” it from someone else. People are born with albinism because they inherit an albinism gene or genes from their parents.
In the most common forms of oculocutaneous albinism, both parents must carry the albinism gene for a child to be born with the condition. Even if both parents carry the gene, the chance of each of their children being born with albinism is one in four.
If just one parent has the gene and the other parent has a normal pigment gene, their children won’t have oculocutaneous albinism. But each child will have a one in two chance of being a “carrier” of an albinism gene. If a child who carries the gene grows up to have a baby with someone who also does, there’s a one in four chance that their baby may have albinism. Since most people who carry an albinism gene don’t show any signs of the condition, a baby with albinism can be born to parents whose coloring is typical for people of their ethnic group.
The most common form of ocular albinism affects only males who have inherited an albinism gene from their mothers. Some females can have a milder form of the condition if they have inherited this gene.
Prevention of albinism
If a family member has albinism, a genetic counselor can help you understand your chances of having a future child with albinism. He or she can also explain the available tests and help you figure out the pros and cons of testing for your family member.
Some children with albinism are born with pinkish-white skin and white hair. Their eyes are usually light grey, blue or hazel, although they can look pink in the light.
People with albinism usually have poor vision. Glasses can help, but some have poor vision even with glasses. Some people with albinism also have nystagmus, which is involuntary flicking movements of the eye.
Although the most recognizable form of albinism results in white hair and pinkish skin, skin coloring (pigmentation) can range from white to brown, and may be nearly the same as that of parents or siblings without albinism.
For some people with albinism, skin pigmentation never changes. For others, melanin production may begin or increase during childhood and the teen years, resulting in slight changes in pigmentation. With exposure to the sun, some people may develop:
- Moles, with or without pigment — moles without pigment are generally pink-colored
- Large freckle-like spots (lentigines)
- The ability to tan
Hair color can range from very white to brown. People of African or Asian descent who have albinism may have hair color that’s yellow, reddish or brown. Hair color may also darken by early adulthood.
Eye color can range from very light blue to brown and may change with age.
The lack of pigment in the colored part of the eyes (irises) makes them somewhat translucent. This means that the irises can’t completely block light from entering the eye. Because of this, very light-colored eyes may appear red in some lighting. This occurs because you’re seeing light reflected off the back of the eye and passing back out through the iris again — similar to the red-eye that occurs in a flash photo.
Signs and symptoms of albinism related to eye function include:
- Rapid, involuntary back-and-forth movement of the eyes (nystagmus)
- Inability of both eyes to stay directed at the same point or to move in unison (strabismus)
- Extreme nearsightedness or farsightedness
- Sensitivity to light (photophobia)
- Abnormal curvature of the front surface of your eye or the lens inside your eye (astigmatism), which causes blurred vision
Usually, albinism is picked up at birth. Genetic testing can help confirm the diagnosis.
A complete diagnostic work-up for albinism includes a:
- Physical exam
- Description of changes in pigmentation
- Thorough exam of the eyes
- Comparison of your child’s pigmentation to that of other family members
A medical doctor specializing in vision and eye disorders (ophthalmologist) should conduct your child’s eye exam. The exam will include an assessment of potential nystagmus, strabismus and photophobia. The doctor will also use a device to visually inspect the retina and determine if there are signs of abnormal development. A simple test can measure the brain waves produced when light or a reversing pattern is flashed into each eye. This can indicate the presence of misrouted optical nerves.
If your child has only one eye impairment, such as nystagmus, another condition may be the cause. Disorders other than albinism can affect skin pigmentation, but these don’t cause all of the visual problems associated with albinism.
Albinism can’t be “cured.” But it only rarely leads to serious health problems.
Because most people with albinism don’t have health problems, treatment — apart from vision care — isn’t usually necessary.
People with Hermansky-Pudlak and Chediak-Higashi syndromes usually require regular specialized care to prevent complications.
People with albinism have a higher risk than others of sunburn, skin problems and skin cancer. So people with alibinism need to take certain precautions, such as wearing sunglasses and sunscreen when outdoors.
When health problems are serious, doctors usually can treat the symptoms.
Proper eye care and monitoring skin for signs of abnormalities are especially important to your child’s health.
- Your child will most likely need to wear prescription lenses, and he or she should receive annual eye exams by an ophthalmologist. Although surgery is rarely part of treatment for albinism, your ophthalmologist may recommend surgery on optical muscles to minimize nystagmus. Surgery to correct strabismus may make the condition less noticeable, but it won’t improve vision.
- Your doctor should conduct an annual assessment of your child’s skin to screen for skin cancer or lesions that can lead to cancer. Adults with albinism need annual eye and skin exams throughout their lives.
Eye problems in albinism result from the abnormal development of the eye because of a lack of pigment and often include:
- Nystagmus: Regular horizontal back and forth movement of the eyes
- Strabismus: Muscle imbalance of the eyes, “crossed eyes” (esotropia), “lazy eye” or an eye that deviates out (exotropia)
- Photophobia: Sensitivity to bright light and glare
- Refractive Error: People with albinism may be either farsighted or nearsighted and usually have astigmatism
- Foveal hypoplasia: The retina, the surface inside the eye that receives light, does not develop normally before birth and in infancy
- Optic nerve misrouting: The nerve signals from the retina to the brain do not follow the usual nerve routes
The iris, the colored area in the center of the eye, has very little or no pigment to screen out stray light coming into the eye. Light normally enters the eye only through the pupil, the dark opening in the center of the iris, but in albinism light can pass through the iris as well.
For the most part, treatment consists of visual rehabilitation. Surgery to correct strabismus may improve the appearance of the eyes. However, since surgery will not correct the misrouting of nerves from the eyes to the brain, surgery will not improve eyesight or fine binocular vision. In the case of esotropia or “crossed eyes,” surgery may help vision by expanding the visual field (the area that the eyes can see while looking at one point). Surgical intervention is also available to minimize nystagmus.
People with albinism are sensitive to glare, but they do not prefer to be in the dark, and they need light to see just like anyone else. Sunglasses or tinted contact lenses may help outdoors. Indoors, it is important to place lights for reading or close work over a shoulder rather than in front.
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 jobs, hobbies or other usual activities. Some people do well using bifocals which have a strong reading lens, prescription reading glasses or contact lenses. Others use handheld magnifiers or special small telescopes, and some prefer to use screen magnification products on computers.
Some people with albinism use bioptics, glasses which have small telescopes mounted on, in or behind their regular lenses so that one can look through either the regular lens or the telescope. Some states allow the use of bioptic telescopes for driving.
Optometrists or ophthalmologists who are experienced in working with low vision patients can recommend various optical aids. Clinics should provide instruction in their use. The American Foundation for the Blind 8) maintains a directory of low vision clinics. In Canada, support is available from the Canadian National Institute for the Blind 9).
Lifestyle and home remedies
You can help your child learn self-care practices that should continue into adulthood:
- Use low vision aids, such as a hand-held magnifying glass, a monocular or a magnifier that attaches to glasses.
- Apply sunscreen with a sun protection factor (SPF) of at least 30 that protects against both UVA and UVB light.
- Avoid high-risk sun exposure, such as being outside in the middle of the day, at high altitudes, and on sunny days with thin cloud cover.
- Wear protective clothing, including long-sleeved shirts, long pants and broad-rimmed hats.
- Protect eyes by wearing dark, UV-blocking sunglasses or transition lenses that darken in bright light.
Coping and support
Coping with vision impairment
Many people with albinism develop coping skills to adjust to vision impairments. Tilting the head to one side may minimize the effect of nystagmus and improve vision. Holding a book very close can make it easier to read without causing any harm to the eyes.
Coping with educational challenges
Despite visual handicaps and abnormal optic nerve pathways, children with albinism are developmentally normal. If your child has albinism, begin early to work with teachers and school administrators to facilitate measures to help your child adapt. These may include sitting in the front of the class, using large-print books or a tablet computer for learning, avoiding bright light in the learning setting, or allowing more time for taking tests.
If necessary, start with educating the school professionals about what albinism is and how it affects your child. Also ask about services the school can provide to assess your child’s needs.
Adjustments to the classroom environment that may help your child include:
- A seat near the front of the classroom
- A tablet computer that can be synced to an interactive whiteboard (SMART board) at the front of the room, allowing the child to sit farther back in the classroom
- Handouts of the content written on boards or overhead screens
- High-contrast printed documents, such as black type on white paper rather than colored print or paper
- Large-print textbooks
- Other options, such as showing the child how to enlarge font size on a computer screen
Help your child develop skills to deal with other people’s reactions to albinism:
- Encourage your child to talk to you about experiences and feelings.
- Practice responses to teasing or embarrassing questions.
- Find a peer support group or online community through agencies such as the National Organization for Albinism and Hypopigmentation 10).
- Seek the services of a mental health professional, who can help you and your child develop healthy communication and coping skills.
References [ + ]
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|3.||↵||Albinism. MedlinePlus. https://medlineplus.gov/ency/article/001479.htm|
|4, 10.||↵||National Organization for Albinism and Hypopigmentation. http://www.albinism.org|
|6.||↵||American College of Medical Genetics. https://www.acmg.net/|
|7.||↵||National Society of Genetic Counselors. https://www.nsgc.org/|
|8.||↵||American Foundation for the Blind. https://www.afb.org/default.aspx|
|9.||↵||Canadian National Institute for the Blind. http://www.cnib.ca/en/Pages/default.aspx|