Questions and answers on Albinism
What is albinism?
The word “albinism” refers to a group of inherited conditions. People with albinism have little or no pigment in the eyes, skin, and hair (or in some cases in the eyes alone). They have inherited from their parents an altered copy of genes that does not work correctly. The altered gene does not allow the body to make the usual amounts of a pigment called melanin.
Albinism affects people from all races. The parents of most children with albinism have normal hair and eye color for their ethnic background, and do not have a family history of albinism.
What is Melanin?
Melanin is a dark compound that is called a photoprotective pigment. The major role of melanin pigment in the skin is to absorb the ultraviolet (UV) light that comes from the sun so that the skin is not damaged. Sun exposure normally produces a tan which is an increase in melanin pigment in the skin. Many people with albinism do not have melanin pigment in their skin and do not tan with exposure to the sun. As a result, their skin is sensitive to the sun light and they develop a sun burn.
Melanin pigment is important in other areas of the body, such as the eye and the brain, but it is not known what the melanin pigment does in these areas. Melanin pigment is present in the retina and the area of the retina called the fovea does not develop correctly if melanin pigment in not present in the retina during development. The other areas of the retina develop normally whether or not melanin pigment is present. The nerve connections between the retina and the brain are also altered if melanin pigment is not present in the retina during development. The iris has melanin pigment and this makes the iris opaque to light (no light goes through an opaque iris). Iris pigment in albinism is reduced, and the iris is translucent to light, but the iris develops and functions normally in albinism.
What Are the Problems with Albinism?
The eye needs melanin pigment to develop normal vision. People with albinism have impairment of vision because the eye does not have a normal amount of melanin pigment during development.
The skin needs pigment for protection from sun damage, and people with albinism often sunburn easily. In tropical areas, many people with albinism who do not protect their skin get skin cancers.
There are several less common types of albinism which involve other problems also, such as mild problems with blood clotting, or problems with hearing
Albinism may cause social problems, because people with albinism look different from their families, peers, and other members of their ethnic group.
Growth and development of a child with albinism should be normal and intellectual development is normal. Developmental milestones should be achieved at the expected age. General health of a child and an adult with albinism is normal, and the reduction in melanin pigment in the skin, hair and the eyes should have no effect on the brain, the cardiovascular system, the lungs, the gastrointestinal tract, the genitourinary system, the musculoskeletal system, or the immune system. Life span is normal.
What Eye Problems Result from Albinism?
People with albinism, whether it involves the eyes alone or involves the skin and the hair, often have several problems:
People with albinism are “not blind,” but their vision (also called visual acuity) is not normal, and cannot be corrected completely with glasses. Extreme far-sightedness or near-sightedness, and astigmatism are common and correction with glasses can improve acuity in many people with albinism. Corrected visual acuity ranges from 20/20 (can see at 20 feet what should be seen at 20 feet; normal) to 20/400 (see at 20 feet what should be seen at 400 feet; legally blind). Normal or near-normal vision is unusual, however, even when glasses are worn.
Nystagmus, which is an involuntary movement of the eyes back and forth. Many people with albinism learn to use a head tilt or turn that decreases the movement and may improve vision.
Strabismus, which means that the eyes do not fixate and track together. Despite this condition, people with albinism do have some depth perception, although it is not as sharp as when both eyes can work together.
Sensitivity to light, which is called photophobia. The iris allows “stray” light to enter the eye and cause sensitivity. Contrary to a common idea, this sensitivity does not limit people with albinism from going out into the sunlight.
Iris color is usually blue/gray or light brown. It is a common notion that people with albinism must have red eyes, but in fact the color of the iris varies from a dull gray to blue to brown. (A brown iris is common in ethnic groups with darker pigmentation.) Under certain lighting conditions, there is a reddish or violet hue reflected through the iris, which has very little pigment. This reddish reflection comes from the retina, which is the surface lining the inside of the eye. This reddish reflection is similar to that which occurs when a flash photograph is taken of a person looking directly at the camera, and the eyes appear red. With some types of albinism the red color can reflect back through the iris as well as through the pupil.
One major abnormality of the eye in albinism involves lack of development of the fovea (also known as foveal hypoplasia). The fovea is a small but most important area of the retina in the inside of the eye. The retina contains the nerve cells that detect the light entering the eye and transmit the signal for the light to the brain. The fovea is the area of the retina which allows sharp vision, such as reading, and this area of the retina does not develop in albinism. It is not known why the fovea does not develop normally with albinism, but it is related to the lack of melanin pigment in the retina during development of the eye. The developing eye seems to need melanin for organizing the fovea.
The major abnormality of the eye in albinism involves the development of the nerves that connect the retina to the brain. People with albinism have an unusual pattern for sending nerve signals from the eye to the brain. The nerve connections from the eye to the vision areas of the brain are organized differently from normal. This unusual pattern for nerve signals probably prevents the eyes from working well together, and causes reduced depth perception.
Strabismus is also common in albinism and is related to the altered development of the optic nerves. The strabismus in albinism is usually not severe and tends to alternate between involving the right and the left eye.
What can be done for the Eye Problems?
Ophthalmologists and optometrists can help people with albinism compensate for their eye problems, but they cannot cure them.
For help with visual acuity, eye doctors experienced in low vision can prescribe a variety of devices. No one device can serve the needs of all persons in all situations, since different occupations and hobbies require the use of vision in different ways. Young children may simply need glasses, and older children can sometimes benefit from bifocal glasses. Low vision clinics may prescribe telescopic lenses mounted on glasses, sometimes called bioptics, for close-up work as well as for distant vision. Recently smaller and lighter telescopes have been developed; however, ordinary glasses or bifocals with a strong reading correction may serve well for many people with albinism.
For nystagmus, research has searched for an effective treatment which helps in all cases. Attempted treatments to control nystagmus have included biofeedback, contact lenses, and surgery. The most promising may be eye muscle surgery that reduced the movement of the eyes; however, vision may not improve in all cases due to other associated eye abnormalities.
People with albinism may find ways of reducing nystagmus while reading, such as placing a finger by the eye, or tilting the head at an angle where nystagmus is dampened.
For strabismus, ophthalmologists prefer to treat infants starting at about six months age, before the function of their eyes has developed fully. They may recommend that parents patch one eye to promote the use of the non-preferred eye. In other cases, the alignment of the eyes improves with the wearing of glasses. Correction of strabismus by surgery or by injection of medicine into the muscles around the eyes does not completely correct the problem with both eyes fixing on one point. Although these treatments may improve the alignment of the eyes and enhance psycho-social development and interpersonal interactions, they cannot correct the improper routing of the nerves to the brain. Depth perception is not improved with eye muscle surgery.
For photophobia, eye doctors can prescribe dark glasses that shield the eyes from bright light, or photochromic lenses that darken on exposure to brighter light. There is no proof that dark glasses will improve vision, even when used at a very early age, but they may improve comfort.
Many children and adults with albinism do not like tinted lenses, and benefit more from wearing a cap or a visor when outdoors in the sun.
What can be done to Help Children with Albinism in School?
Most children with albinism should function in a mainstream classroom environment, provided the school gives specific attention to their special needs for vision. Contact with the school system should begin well before kindergarten, since school systems provide preschool services to children with disabilities. Preschool evaluations allow parents and teachers to form an Individual Education Plan for the child. The use of Braille is not necessary, and, if a trial of Braille is given, children with albinism will read the dots visually.
Children with albinism often prefer to read with a head tilt and usually hold the page close to the eyes. Occasionally it can be difficult to get them to use their glasses, as they do not notice significant improvement in their vision when glasses are used. Furthermore, use of glasses or books with large print can be difficult because of peer pressure.
Various classroom aids help children with albinism:
High contrast written material: Children with albinism have a hard time reading worksheets and papers that are light or low contrast. Black on white high contrast material is better.
Large-type textbooks: The school can usually obtain large type editions from the publishers of their regular textbooks. Because children with albinism often have difficulty keeping track of their place on the page while shifting back and forth between a textbook and a worksheet, it may help to allow them to write in the textbook. Worksheets may need to be copied on a machine that enlarges print size. Children with albinism do not always need large-type materials, however, and large type should not substitute for poor optical visual aids. Use of audio tapes may be preferable to voluminous reading.
Copies of the teacher’s board notes: The child with low vision can read the notes close-up while classmates read the board.
Various optic devices: Hand-held monoculars, telescopic lenses mounted over eye glasses, video enlargement machines (closed circuit TV), and other types of magnifiers may help some people with albinism.
Computers: Children with albinism should begin key-boarding skills early, since computers with software for large character screen display can help greatly with writing projects.
Prescription of appropriate classroom visual aids requires teamwork of the student, parent, classroom teacher, vision resources teacher, and an optometrist or ophthalmologist experienced in working with persons with low vision.
How Much Time Can a Person with Albinism Stay in the Sun?
Most people with albinism do not tan, and they burn easily on exposure to the sun. People with albinism who develop increasing amounts of hair and skin pigment as they get older may not be bothered by the sun, and may tan with sun exposure. If sun exposure produces sunburn, then the skin must be protected to prevent burning and damage.
Sunburn is skin damage from exposure to ultraviolet light, which is a part of sunlight that is not visible to the human eye. Redness develops 2 to 6 hours after exposure to ultraviolet light, and sunburn may not turn completely red until as long as 24 hours after the exposure. As a result a sunburn can worsen after a person leaves the sun. Prolonged sun exposure in a person who does not tan well is associated with the development of skin cancer. This can be prevented with correct protection of the skin from the ultraviolet radiation of the sun.
It is difficult to state a general rule for the number of hours in the sun that people with albinism can tolerate, since the intensity of the ultraviolet light varies a great deal, depending upon the time of day and year, and the environmental conditions:
Latitude: A person who can tolerate one hour of sun in Florida without burning can tolerate two hours of sun in New Jersey under the same conditions.
Altitude: Each 1000-foot increase in altitude adds 4% to the intensity of the sun burning rays. The intensity of sunlight at 5000 feet is about 20% greater than at sea level.
Surroundings: Sand reflects 25% or more of ultraviolet rays, so that it is possible to get sunburned while sitting in the shade on a beach. Fresh snow reflects 70 to 90% of ultraviolet rays. Reflected light may burn areas which are usually shaded, such as those under the nose or chin.
Weather: A bright day with a thin cloud cover has 60 to 80% of the ultraviolet rays present on a clear day. Clouds can cool and give a false impression that there is little risk of sunburn.
Water: As much as 96% of ultraviolet rays can penetrate clear water.
Season: The greatest intensity of ultraviolet light occurs at the summer solstice, about June 22. May 1 has as much intensity as August 15.
Time of day: Most ultraviolet rays come between 10 a.m. and 2 p.m. Standard Time, or 11 a.m. and 3 p.m. Daylight Savings Time.
Clothing: Up to 50% of the ultraviolet rays can go through wet clothing, such as tee shirts worn for swimming. Colored clothing and denser-woven clothing allow less light penetration. Some tee shirts, such as Frogskin¨ tee shirts, are designed to protect against sun even when wet. .
How do we classify albinism?
Two main categories of albinism are: “oculocutaneous albinism” or “OCA” which means that melanin pigment is missing in the skin, the hair, and the eyes; and “ocular albinism” or “OA” which means that the melanin pigment is missing mainly in the eyes, and the skin and hair appear normal. OCA is more common than OA.
How can you determine the type of albinism present?
It is usually possible to determine the type of albinism present with a careful history of pigment development and an examination of the skin, hair and eyes. The only type of albinism that has white hair at birth is OCA1. Individuals with other types of OCA will have some hair pigment at birth, although it may be very slight in amount. It can be difficult to tell if the hair is completely white or very lightly pigmented in a very young child, and changes in pigment over time will usually help clarify the OCA type present.
The most accurate test for determining the specific type of albinism is a gene test. A small sample of blood is obtained from the affected individual and the parents as a source of DNA, the chemical that carries the ‘genetic code’ of each gene. By a complex process, a genetic laboratory can “sequence” the code of the DNA, to identify the changes (mutations) in the gene that cause albinism in the family. The test is useful only for families that contain individuals with albinism, and cannot be performed practically as a screening test for the general population. None of the tests available are capable of detecting all of the mutations of the genes that cause albinism, and responsible mutations cannot be detected in a small number of individuals and families with albinism.
The test can be used to determine if a fetus has albinism. For this purpose a sample would be obtained by amniocentesis, a procedure which involves using a needle to draw fluid from the uterus, at 16 to 18 weeks gestation. Those considering such testing should be aware that given proper support children with albinism can function well and have normal life spans.
Can people with albinism have Children?
Albinism does not limit the ability of an individual with albinism to have children. The children may or may not have albinism, depending on the genes in partner of the affected individual
Do people with albinism live a normal lifespan?
In general, people with albinism have a normal lifespan. Any medical problems are similar to those in the rest of the population. Skin cancer may occur, but is usually curable.
Do people with albinism have normal intelligence?
Albinism does not cause mental impairment or developmental delay. Individuals with albinism pursue a wide range of career; their options are limited only by their visual impairment. A child or an adult with albinism who has developmental problems must be evaluated for another cause of these problems, because developmental delays of problems are not expected with albinism.
What Causes Albinism? Why are children born with it?
Albinism is genetic. It is inherited. It is passed on from one generation to the next in the genes. Genes are contained in the egg and the sperm that combine at conception to start the process of forming a baby. Genes act as blueprints that tell the system how to do its work. In the case of albinism, the genes involved are those that tell the eyes or skin how to make melanin pigment.
Each cell in the body has two copies of each gene- one version from the mother and one version from the father. For OCA, the individual with albinism has received an albinism gene from both parents, and both versions of his blueprint for making pigment are incorrect.
If a person carries one normal copy of a gene and one altered or albinism copy of a gene, he or she still has one blueprint that will provide enough information to make pigment. That means that he or she will have normal eye and skin color. For OCA, parents carry an albinism gene with an incorrect version of the blueprint, but they have normal pigmentation, because they still have one normal gene with a normal version of the blueprint.
About 1 in 70 people carries a gene for OCA. Suppose a man and a woman each carry an altered copy of the same gene and have normal coloration. They each have a normal copy and an albinism copy of the gene, and will pass one of these two copies when they conceive a baby. They each have a 1 in 2 chance of passing on the albinism copy of the gene to their baby. As a result, for each pregnancy there is a 1 in 4 chance (1/2 x 1/2) that their baby will get two copies of the gene for albinism, in which case the baby will have no normal blueprint for making pigment, and will have albinism. This description of the inheritance of albinism applies to the different types of OCA.