Albinism

Definition

Albinism is an inherited condition present at birth, characterized by a lack of pigment that normally gives color to the skin, hair, and eyes. Many types of albinism exist, all of which involve lack of pigment in varying degrees. The condition, which is found in all races, may be accompanied by eye problems and may lead to skin cancer later in life.

Description

Albinism is a rare disorder found in fewer than five people per 100,000 in the United States and Europe. Other parts of the world have a much higher rate; for example, albinism is found in about 20 out of every 100,000 people in southern Nigeria.

There are 10 types of the most common form of the condition, known as "oculocutaneous albinism," which affects the eyes, hair, and skin. In its most severe form, hair and skin remain pure white throughout life. People with a less severe form are born with white hair and skin, which turn slightly darker as they age. Everyone with oculocutaneous albinism experiences abnormal flickering eye movements (nystagmus ) and sensitivity to bright light. There may be other eye problems as well, including poor vision and crossed or "lazy" eyes (strabismus).

The second most common type of the condition is known as "ocular" albinism, in which only the eyes lack color; skin and hair are normal. There are five forms of ocular albinism; some types cause more problems-especially eye problems-than others.

Causes and symptoms

Every cell in the body contains a matched pair of genes, one inherited from each parent. These genes act as a sort of "blueprint" that guides the development of a fetus.

Albinism is an inherited problem caused by a flaw in one or more of the genes that are responsible for directing the eyes and skin to make melanin (pigment). As a result, little or no pigment is made, and the child's skin, eyes and hair may be colorless.

In most types of albinism, a recessive trait, the child inherits flawed genes for making melanin from both parents. Because the task of making melanin is complex, there are many different types of albinism, involving a number of different genes.

It's also possible to inherit one normal gene and one albinism gene. In this case, the one normal gene provides enough information in its cellular blueprint to make some pigment, and the child will have normal skin and eye color. They "carry" one gene for albinism. About one in 70 people are albinism carriers, with one flawed gene but no symptoms; they have a 50% chance of passing the albinism gene to their child. However, if both parents are carriers with one flawed gene each, they have a 1 in 4 chance of passing on both copies of the flawed gene to the child, who will have albinism. (There is also a type of ocular albinism that is carried on the X chromosome and occurs almost exclusively in males because they have only one X chromosome and, therefore, no other gene for the trait to override the flawed one.)

Symptoms of albinism can involve the skin, hair, and eyes. The skin, because it contains little pigment, appears very light, as does the hair.

Although people with albinism may experience a variety of eye problems, one of the myths about albinism is that it causes people to have pink or red eyes. In fact, people with albinism can have irises varying from light gray or blue to brown. (The iris is the colored portion of the eye that controls the size of the pupil, the opening that lets light into the eye.) If people with albinism seem to have reddish eyes, it's because light is being reflected from the back of the eye (retina) in much the same way as happens when people are photographed with an electronic flash.

People with albinism may have one or more of the following eye problems:

• They may be very far-sighted or near-sighted, and may have other defects in the curvature of the lens of the eye (astigmatism ) that cause images to appear unfocused.
• They may have a constant, involuntary movement of the eyeball called nystagmus.
• They may have problems in coordinating the eyes in fixing and tracking objects (strabismus), which may lead to an appearance of having "crossed eyes" at times. Strabismus may cause some problems with depth perception, especially at close distances.
• They may be very sensitive to light (photophobia) because their irises allow "stray" light to enter their eyes. It's a common misconception that people with albinism shouldn't go out on sunny days, but wearing sunglasses can make it possible to go outside quite comfortably.

In addition to the characteristically light skin and eye problems, people with a rare form of albinism called Hermansky-Pudlak Syndrome (HPS) also have a greater tendency to have bleeding disorders, inflammation of the large bowel (colitis), lung (pulmonary) disease, and kidney (renal) problems.

Diagnosis

It's not always easy to diagnose the exact type of albinism a person has; there are two tests available that can identify only two types of the condition. Recently, a blood test has been developed that can identify carriers of the gene for some types of albinism; a similar test during amniocentesis can diagnose some types of albinism in an unborn child. A chorionic villus sampling test during the fifth week of pregnancy may also reveal some types of albinism.

The specific type of albinism a person has can be determined by taking a good family history and examining the patient and several close relatives.

The "hairbulb pigmentation test" is used to identify carriers by incubating a piece of the person's hair in a solution of tyrosine, a substance in food which the body uses to make melanin. If the hair turns dark, it means the hair is making melanin (a "positive" test); light hair means there is no melanin. This test is the source of the names of two types of albinism: "ty-pos" and "ty-neg."

The tyrosinase test is more precise than the hairbulb pigmentation test. It measures the rate at which hair converts tyrosine into another chemical (DOPA), which is then made into pigment. The hair converts tyrosine with the help of a substance called "tyrosinase." In some types of albinism, tyrosinase doesn't do its job, and melanin production breaks down.

Treatment

There is no treatment that can replace the lack of melanin that causes the symptoms of albinism. Doctors can only treat, not cure, the eye problems that often accompany the lack of skin color. Glasses are usually needed and can be tinted to ease pain from too much sunlight. There is no cure for involuntary eye movements (nystagmus), and treatments for focusing problems (surgery or contact lenses) are not effective in all cases.

KEY TERMS

Amino acids— Natural substances that are the building blocks of protein. The body breaks down the protein in food into amino acids, and then uses these amino acids to create other proteins. The body also changes amino acids into melanin pigment.

Astigmatism— An eye condition in which the lens doesn't focus light evenly on the retina, leading to problems with visual sharpness.

Carrier— A person with one normal gene and one faulty gene, who can pass on a condition to others without actually having symptoms.

DNA— The abbreviation for "deoxyribonucleic acid," the primary carrier of genetic information found in the chromosomes of almost all organisms. The entwined double structure allows the chromosomes to be copied exactly during cell division.

DOPA— The common name for a natural chemical (3, 4-dihydroxyphenylalanine) made by the body during the process of making melanin.

Enzyme— A protein that helps the body convert one chemical substance to another.

Gene— The basic unit of genetic material carried in a particular place on a chromosome. Genes are passed on from parents to child when the sperm and egg unite during conception.

Hairbulb— The root of a strand of hair from which the color develops.

Hermansky-Pudlak Syndrome (HPS)— A rare type of albinism characterized by a problem with blood clotting and a buildup of waxy material in lungs and intestines.

Melanin— Pigment made in the hair, skin and eyes.

Nystagmus— An involuntary back-and-forth movement of the eyes that is often found in albinism.

Strabismus— Crossed or "lazy" eyes, often found in albinism.

Tyrosine— A protein building block found in a wide variety of foods that is used by the body to make melanin.

Tyrosinase— An enzyme in a pigment cell which helps change tyrosine to DOPA during the process of making melanin.

Crossed eyes (strabismus) can be treated during infancy, using eye patches, surgery or medicine injections. Treatment may improve the appearance of the eye, but it can do nothing to cure the underlying condition.

Patients with albinism should avoid excessive exposure to the sun, especially between 10 a.m. and 2 p.m. If exposure can't be avoided, they should use UVA-UVB sunblocks with an SPF of at least 20. Taking beta- carotene may help provide some skin color, although it doesn't protect against sun exposure.

Prognosis

In the United States, people with this condition can expect to have a normal lifespan. People with albinism may experience some social problems because of a lack of understanding on the part of others. When a member of a normally dark-skinned ethnic group has albinism, he or she may face some very complex social challenges.

One of the greatest health hazards for people with albinism is excessive exposure to sun without protection, which could lead to skin cancer. Wearing opaque clothes and sunscreen rated SPF 20, people with albinism can safely work and play outdoors safely even during the summer.

Prevention

Genetic counseling is very important to prevent further occurrences of the conditon.

Resources

BOOKS

National Association for the Visually Handicapped. Larry: A Book for Children with Albinism Going to School. New York: National Association for the Visually Handicapped.

ORGANIZATIONS

Albinism World Alliance. 〈http://www.albinism.org/awa.html〉.

American Foundation for the Blind. 15 W. 16th St., New York, NY 10011. (800) AFB-LIND.

Hermansky-Pudlak Syndrome Network, Inc. One South Road, Oyster Bay, NY 11771-1905. (800) 789-9477. 〈[email protected]〉.

National Organization for Albinism and Hypopigmentation (NOAH). 1530 Locust St., #29, Philadelphia, PA 19102-4415. (800) 473-2310. 〈http://www.albinism.org〉.

Albinism

Definition

Albinism is an inherited condition that is present at birth. It is characterized by a lack of melanin, the pigment that normally gives color to the skin, hair, and eyes. Many types of albinism exist, all of which involve lack of pigment in varying degrees. The condition, which is found in all races, may be accompanied by eye problems and may ultimately lead to skin cancer .

Description

The most common type of albinism is oculocutaneous albinism, which affects the eyes, hair, and skin. In its most severe form, hair and skin remain completely white throughout life. People with a less severe form are born with white hair and skin that turn slightly darker as they age. Everyone with oculocutaneous albinism experiences abnormal flickering eye movements (nystagmus ) and sensitivity to bright light. There may be other eye problems as well, including poor vision and crossed or "lazy" eyes (strabismus ).

The second most common type of the condition is known as ocular albinism, in which only the eyes lack color; skin and hair are normal. Some types of ocular albinism cause more problems, especially eye problems, than others.

Albinism is also referred to as hypopigmentation.

Demographics

Albinism is a rare disorder found in fewer than five people per 100,000 in the United States and Europe. Although albinism can affect all races, other parts of the world have a much higher rate; for example, albinism is found in about 20 out of every 100,000 people in southern Nigeria. 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.

Causes and symptoms

Albinism is an inherited problem caused by an alteration in one or more of the genes that are responsible for directing the eyes and skin to produce or distribute melanin, which is a photoprotective pigment that absorbs ultraviolet (UV) light coming 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, do not tan with exposure to the sun, and as a result develop sunburn . Over time, people with albinism may develop skin cancers if they do not adequately protect their skin from sun exposure.

Melanin is also important in the eyes and brain, but it is not known what role melanin plays in those areas. Parts of the retina do not develop correctly if melanin pigment is not present during development. Also nerve connections between the retina and brain are altered if melanin is not present in the retina during development.

Albinism is a autosomal recessive disease, which means that a person must have two copies of the defective gene to exhibit symptoms of the disease. The child therefore inherits one defective gene responsible for making melanin from each parents. Because the task of making melanin is complex, there are many different types of albinism, involving a number of different genes.

It is also possible to inherit one normal gene and one albinism gene. In this case, the one normal gene provides enough information to make some pigment, and the child has normal skin and eye color. The child has one gene for albinism. About one in 70 people are albinism carriers, with one defective gene but no symptoms; they have a 50 percent chance of passing the albinism gene to their child. However, if both parents are carriers with one defective gene each, they have a one in four chance of passing on both copies of the defective gene to the child, who will have albinism. There is also a type of ocular albinism that is carried on the X chromosome and occurs almost exclusively in males because they have only one X chromosome and, therefore, no other gene for the trait to override the defective one.

People with albinism may experience a variety of eye problems, including one or more of the following:

• They may be very far-sighted or near-sighted and may have other defects in the curvature of the lens of the eye (astigmatism) that cause images to appear unfocused.
• They may have a constant, involuntary movement of the eyeball called nystagmus.
• They may have problems in coordinating the eyes in fixing and tracking objects (strabismus), which may lead to an appearance of having "crossed eyes" at times.
• They may have reduced depth perception due to altered nerve connections from the retina to the brain.
• Their eyes may be very sensitive to light (photophobia) because their irises allow stray light to enter their eyes. It is a common misconception that people with albinism should not go outside on sunny days, but wearing sunglasses can make it possible to go outside quite comfortably.

One of the myths about albinism is that it causes people to have pink or red eyes. In fact, people with albinism can have irises varying from light gray or blue to brown. (The iris is the colored portion of the eye that controls the size of the pupil, the opening that lets light into the eye.) If people with albinism seem to have reddish eyes, it is because light is being reflected from the back of the eye (retina) in much the same way as happens when people are photographed with an electronic flash. In addition, albinism does not cause blindness.

In addition to characteristically light skin and eye problems, people with a rare form of albinism called Hermansky-Pudlak syndrome (HPS) also have a greater tendency to have bleeding disorders, inflammation of the large bowel (colitis), lung (pulmonary) disease, and kidney (renal) problems.

When to call the doctor

The doctor should be called when a person with albinism exhibits symptoms such as photophobia that cause discomfort. Also the doctor should be consulted if there are any skin changes that might be an early sign of skin cancer.

The parent of a child with albinism should also call the doctor if the child bruises easily or has unusual bleeding, such as repeated nosebleeds or bloody diarrhea . The child may have the rare Hermansky-Pudlak syndrome, which requires additional medical care.

Diagnosis

It is not always easy to diagnose the exact type of albinism a person has. The specific type is sometimes determined by developing a thorough family history and by examining the patient and several close relatives. In the early 2000s, a blood test has been developed that can identify carriers of the gene for some types of albinism; a similar test during amniocentesis can diagnose some types of albinism in an unborn child. A chorionic villus sampling test during the fifth week of pregnancy may also reveal some types of albinism.

There are also two tests available that can identify two types of the condition. The hairbulb pigmentation test is used to identify carriers by incubating a piece of the person's hair in a solution of tyrosine, a substance in food which the body uses to make melanin. If the hair turns dark, it means the hair is making melanin (a positive test); light hair means there is no melanin. This test is the source of the names of two types of albinism: "typos" and "ty-neg."

The tyrosinase test is more precise than the hair-bulb pigmentation test. It measures the rate at which hair converts the amino acid tyrosine into another chemical (3,4-dihydroxyphenylalanine, or DOPA), which is then made into pigment. The hair converts tyrosine with the help of an enzyme called tyrosinase. In some types of albinism, a genetic defect in tyrosinase means that the amino acid tyrosine cannot be converted by tyrosinase into melanin.

Treatment

There is no treatment that can replace the lack of melanin that causes the symptoms of albinism. In addition, doctors can only treat, but not cure, the eye problems that often accompany the lack of skin color. Glasses or corrective lenses and low vision aids, for example, magnifiers, monoculars (handheld telescopes used with only one eye), or bioptics (glasses with small telescopic lenses mounted in the standard lenses) can improve vision but usually cannot correct vision to 20/20. The lenses can be tinted to ease pain from too much sunlight. For reading, children with albinism may or may not need materials with large print text, depending on the severity of their vision problems. There is no cure for involuntary eye movements (nystagmus), and treatments for focusing problems (surgery or contact lenses ) are not effective in all cases.

Crossed eyes (strabismus) can be treated during infancy by using eye patches, surgery, or medicine injections. Treatment may improve the appearance of the eye, but it can do nothing to cure the underlying condition.

KEY TERMS

Amino acid —An organic compound composed of both an amino group and an acidic carboxyl group. Amino acids are the basic building blocks of proteins. There are 20 types of amino acids (eight are "essential amino acids" which the body cannot make and must therefore be obtained from food).

Astigmatism —An eye condition in which the cornea doesn't focus light properly on the retina, resulting in a blurred image.

Carrier —A person who possesses a gene for an abnormal trait without showing signs of the disorder. The person may pass the abnormal gene on to offspring. Also refers to a person who has a particular disease agent present within his/her body, and can pass this agent on to others, but who displays no symptoms of infection.

DNA —Deoxyribonucleic acid; the genetic material in cells that holds the inherited instructions for growth, development, and cellular functioning.

DOPA —The common name for a natural chemical (3,4-dihydroxyphenylalanine) made by the body during the process of making melanin.

Enzyme —A protein that catalyzes a biochemical reaction without changing its own structure or function.

Gene —A building block of inheritance, which contains the instructions for the production of a particular protein, and is made up of a molecular sequence found on a section of DNA. Each gene is found on a precise location on a chromosome.

Hairbulb —The root of a strand of hair from which growth and coloration of the hair develops.

Hermansky-Pudlak syndrome —A rare type of albinism, most common in the Puerto Rican community, which can cause pigment changes, lung disease, intestinal disorders, and blood disorders.

Melanin —A pigment that creates hair, skin, and eye color. Melanin also protects the body by absorbing ultraviolet light.

Nystagmus —An involuntary, rhythmic movement of the eyes.

Strabismus —A disorder in which the eyes do not point in the same direction. Also called squint.

Tyrosinase —An enzyme in a pigment cell which helps change tyrosine to dopa during the process of making melanin.

Tyrosine —An amino acid synthesized by the body from the essential amino acid phenylalanine. It is used by the body to make melanin and several hormones, including epinephrine and thyroxin.

Patients with albinism should avoid excessive exposure to the sun, especially between 10 a.m. and 2 p.m., and should wear long sleeves and pants if possible. If exposure cannot be avoided, they should use a UVAUVB sunblock with an SPF rating at least 30.

Most children with albinism function satisfactorily in a mainstream classroom as long as the school provides classroom assistance for their vision needs. The child's eye doctor, the classroom teacher, and the school's vision resource teacher should work as a team with the parents to determine what classroom modifications and vision aids will best help the child. The local school district or the state agency for the blind should be contacted during the child's infancy or during preschool years to determine what assistive services might be available for the child. Early intervention allows parents and teachers to develop an educational plan for the child.

Prognosis

In the United States, people with this condition can expect to have a normal lifespan. However, one of the greatest health hazards for people with albinism is excessive exposure to sun without protection, which may lead to skin cancer. Wearing opaque clothes and sunscreen with at least an SPF rating of 30, people with albinism can safely work and play outdoors even during the summer.

Prevention

Genetic counseling should be considered for individuals with a family history of albinism.

Parental concerns

Children with albinism may experience complex social problems because of their unusual appearance, especially when a member of a normally dark-skinned ethnic group has albinism. The eyes of children with albinism may move rapidly and not focus together, and the children may have to squint, tilt their heads, and hold reading materials close in order to see. These behaviors may result in the child being treated badly by peers. Modifications made for the children in the classroom and in physical education classes to compensate for low vision may make them feel even more isolated. Parents often feel that teasing and name-calling, insensitivity, and ignorance are the greatest challenges that they face with regards to their child's albinism. The support and love of these families of children with albinism are essential to helping the children understand and accept themselves. Support groups for the children and for their families, as well as counseling, may be useful for developing means of coping with the social effects of albinism.

Resources

BOOKS

Albinism: A Medical Dictionary, Bibliography, and Annotated Research Guide to Internet References. San Diego, CA: Icon Health Publications, 2003.

Edwards, Lee G. Too White to Be Black and Too Black to Be White: Living with Albinism. Bloomington, IN: AuthorHouse, 2001.

Mitchell, Elizabeth Tromsness. Albinism in the Family: Albinismo en la Familia. Bloomington, IN: AuthorHouse, 2004.

ORGANIZATIONS

Albinism World Alliance. Web site: <www.albinism.org/awa.html>.

American Foundation for the Blind. 11 Penn Plaza, Suite 300 New York, NY 10001. Web site: <www.afb.org/>.

Hermansky-Pudlak Syndrome Network Inc. One South Road, Oyster Bay, NY 11771–1905. Web site: <www.hpsnetwork.org/HTML/frame.html>.

National Organization for Albinism and Hypopigmentation (NOAH). PO Box 959, East Hampstead, NH 03826–0959. Web site: <www.albinism.org>.

WEB SITES

King, Richard A., et al. "Facts about Albinism." International Albinism Center, University of Minnesota. Available online at <www.cbc.umn.edu/iac/facts.htm> (accessed November 8, 2004).

Judith L. Sims Carol A. Turkington

Albinism

Resources

Albinism is a recessive inherited defect in melanin metabolism in which pigment is absent from hair, skin, and eyes (oculocutaneous albinism) or just from the eyes (ocular albinism). Melanin is a dark biological pigment that is formed as an end product of the metabolism of the amino acid tyrosine. When human skin is exposed to sunlight it gradually darkens or tans due to an increase in melanin. Tanning helps protect the underlying skin layers from the sun’s harmful ultraviolet rays.

The most common examples of albinism are the white rats, rabbits, and mice found at pet stores. The characteristic white coats and pink eyes of these albino

animals contrast dramatically with the brown or gray fur and dark eyes of genetically normal rats, rabbits, and mice. Domestic white chickens, geese, and horses are partial albinos. They retain pigment in their eyes, legs, and feet.

In the past, albinos were often regarded with fear or awe. Sometimes they were killed at birth, although albino births were common enough in some groups not to cause any excitement. For example, among the San Blas Indians of Panama, one in approximately 130 births is an albino. In the mid-nineteenth century, albinos were exhibited in carnival sideshows. Whole families were displayed at times and were described as a unique race of night people. They were said to live underground and to come out only at night when the light was dim and would not hurt their eyes.

Albinism is inherent in all races of humans around the world but is most frequently found among some Native American tribes in the southwestern portion of the United States. With proper medical attention, such as what is found in the United States, people with this condition can expect to live a normal lifespan. Albinism is also rare in the world. One person in 17, 000 has some type of albinism in the United States and Europe. Rates are higher in other parts of the world. Researchers have currently identified 10 different types of oculocutaneous albinism and five types of ocular albinism based on clinical appearance. Humans who have oculocutaneous albinism are unable to produce melanin; they have white, yellow, or yellow-brown hair, very light eyes (usually blue or grayish rather than pink), and very fair skin. The irises of their eyes may appear violet or pinkish because they have very little pigment and allow light to reflect back from the reddish retina in the back of the eye. People with albinism may also suffer from a variety optical disorders such as near- or far-sightedness, nystagmus (rapid irregular movement of the eyes back and forth), or strabismus (muscle imbalance of the eyes causing crossed eyes or lazy eye). They are very sensitive to bright light and sunburn easily. They must take great care to remain covered, wear a hat, and apply sunscreen anytime they are outdoors, since their skin is highly susceptible to precancerous and cancerous growths. People with albinism often wear sunglasses or tinted lenses even indoors to reduce light intensity to a more bearable level.

In ocular albinism only the eyes lack melanin pigment, while the skin and hair show normal or near-normal color. People with this condition have a variety of eye disorders because the lack of pigment impairs normal eye development. They are extremely sensitive to bright light and especially to sunlight (photophobia). Treatment of ocular albinism includes the use of visual aids and sometimes surgery for strabismus.

Albinism occurs when melanocytes (melanin-producing cells) fail to produce melanin. This absence of melanin production happens primarily in two ways. In tyrosinase-negative albinism (the most common form), the enzyme tyrosinase is missing from the melanocytes. Tyrosinase is a catalyst in the conversion of tyrosine to melanin. When the enzyme is missing, no melanin is produced. In tyrosinase-positive albinism, a defect in the body’s tyrosine transport system impairs melanin production. One in every 34, 000 persons in the United States has tyrosinase-negative albinism. It is equally common among blacks and whites, while more blacks than whites are affected by tyrosinase-positive albinism. Native Americans have a high incidence to both forms of albinism.

Albinism cannot be cured, but people with this condition can expect to live a normal life span. Protection of the skin and eyes from sunlight is of primary importance for individuals with albinism. The gene carrying the defect that produces albinism is recessive, so both parents must carry this recessive gene in order to produce a child with the condition. When both parents carry the gene (and neither has albinism), there is a one in four chance with each pregnancy that their child will have albinism. The inheritance pattern of ocular albinism is somewhat different. This condition is X-linked, meaning that the recessive gene for ocular albinism is located on the X chromosome. X-linked ocular albinism appears almost exclusively in males who inherit the condition from their mothers. Recently, a blood test has been developed to identify carriers of the gene that causes tyrosinase-negative albinism, and a similar test can identify this condition in the fetus by amniocentesis.

Vitiglio is another pigmentation disorder that resembles partial albinism. In this condition, the skin exhibits stark white patches resulting from the destruction or absence of melanocytes. About 1% of the U.S. population has this disorder and it primarily affects people between the ages of 10 and 30 years. Unlike albinism, the specific cause of vitiglio is not known, although there seems to be a hereditary component, since about 30% of those who have vitiglio have family members with the condition. A link also exists between vitiglio and several other disorders

KEY TERMS

Catalyst— Any agent that accelerates a chemical reaction without entering the reaction or being changed by it.

Melanin— A dark biological pigment found in the hair, skin, and eyes. Melanin absorbs harmful ultraviolet rays and is an important screen against the Sun.

Melanocyte— A melanin-producing cell.

Tyrosinase— An enzyme that catalyzes the conversion of tyrosine to melanin.

Tyrosine— An amino acid that is a precursor of thyroid hormones and melanin.

with which it is often associated, including thyroid dysfunction, Addison’s disease, and diabetes. Chemicals such as phenols may also cause vitiglio.

People with albinism may experience social and psychological problems because of a lack of understanding and prejudice based on appearance on the part of others. Such attitudes toward albinism are similar to those attitudes shown toward minority groups and disabled people. The small number of people inflicted with albinism has led to much isolation within the group. Often times, professional help in the form of therapists or counselors who are well versed in albinism can assist a person dealing with the condition. Better and more widespread understanding about albinism will eliminate some of the problems that people with albinism must deal with on a daily basis.

Resources

BOOKS

Edwards, Lee G. Too White to Be Black and Too Black to Be White: Living With Albinism. Bloomington, IN: Authorhouse Book Publishing Company, 2001.

Icon Health Publications. Albinism. San Diego, CA: Icon Health Publications, 2003.

Mitchell, Elizabeth Tromsness. Albinism in the Family. Bloomington, IN: Authorhouse Book Publishing Company, 2004.

Professional Guide to Diseases. 7th ed. Springhouse, PA: Springhouse Corp., 2001

OTHER

International Albinism Center (IAC). “Home page for IAC.” <http://albinism.med.umn.edu/> (accessed September 29, 2006).

National Organization for Albinism and Hypopigmentation (NOAH). “Home page for NOAH.” <http://www.albinism.org/> (accessed September 29, 2006).

Larry Blaser

Albinism

Definition

Albinism is an inherited condition that causes a lack of pigment in the hair, skin, or eyes.

Description

People with albinism typically have white or pale yellow hair, pale skin, and light blue or gray eyes. Since their irises have little pigment, their eyes may appear pink or violet in different types of light. This is because light is being reflected from the reddish part of the retina in the back of the eye. Their skin usually does not tan and their eyes are often sensitive to light. Many have trouble with vision. Some children may be born with albinism, but develop some pigmentation as they grow older.

In albinism, the body does not produce enough of a pigment called melanin, which creates hair, skin, and eye color. Melanin protects the body by absorbing the sun's ultraviolet light. There are several types of albinism: some affect only the eyes, while others affect the skin and hair or other parts of the body.

Types of albinism

Ocular: A form of albinism that mainly affects the eyes. People with ocular albinism have some pigmentation, but may have lighter skin, hair, and eye color than other family members. Scientists have identified five different types of ocular albinism.

X-linked ocular: This type of albinism occurs mostly in males, who inherit the gene from their mothers. It causes visual disabilities.

Oculocutaneous: A type of albinism that affects the hair, skin, and eyes. Researchers have classified 10 different types of oculocutaneous albinism.

Tyrosinase-negative oculocutaneous: Also known as Type 1A, this is the most severe form of albinism, marked by a total absence of pigment in hair, skin, and eyes. People with this type of albinism have vision problems and sensitivity to sunlight. They also are extremely susceptible to sunburn.

Tyrosinase-positive oculocutaneous: People with this type of albinism have light hair, skin, and eye coloration and fewer visual impairments.

Hermansky-Pudlak syndrome (HPS): This rare type of albinism is common in the Puerto Rican community. Approximately one person in every 1,800 people in Puerto Rico will be affected by it. The lack of pigmentation can vary widely. People with HPS may have white, pale yellow, or brown hair, but it always is lighter than the rest of the population. Their eyes range from blue to brown, and their skin can be creamy white, yellow, or brown. HPS also often causes visual changes, along with other physical symptoms.

Chediak-Higashi syndrome : A rare type of albinism that interferes with white blood cells and the body's ability to fight infection.

Black Locks Albinism Deafness syndrome (BADS): Another rare form of albinism identified by a black lock of hair on the forehead. BADS causes deafness from birth.

Piebaldism: Also known as partial albinism, this condition is marked by patches of white hair or lighter skin blotches on the body.

Genetic profile

Children inherit the genes for albinism from their parents. The parents may have normal pigmentation, but if both the mother and father carry a recessive gene, there is a one in four chance their child will have albinism.

A specific genetic abnormality causes tyrosinasenegative oculocutaneous albinism (Type 1A). In this type, also called "ty-neg albinism," the body is unable to convert the amino acid tyrosine into pigment. The genes for producing the enzymes related to ty-neg albinism are located on chromosome 11 and chromosome 9.

Similarly, scientists believe the gene that causes Hermansky-Pudlak syndrome is on chromosome 10. They are studying two other genes that appear to be involved in melanin pigment formation: the P gene on chromosome 15 and the ocular albinism gene on the X chromosome.

Women who carry the gene for X-linked ocular albinism may have normal vision, but they have a one in two chance of passing it on to their sons. This type of albinism occurs mainly in males because the gene that causes it is located on the X chromosome. Since males only have one X chromosome, genetic abnormalities on this chromosome will almost always be expressed.

Demographics

Albinism affects one in every 17,000 people. All racial groups, including African-Americans and Latinos are affected by albinism. Asians have the lowest incidence of this condition.

Signs and symptoms

Eye problems

The lack of pigment in albinism causes abnormal development in the eye. For example, the iris (the colored ring around the center of the eye), which normally acts as a filter, may let too much light into the eye. Communication between the retina (the surface inside the eye that absorbs light) and the brain may also be altered in people with albinism, causing a lack of depth perception. These changes can lead to visual impairments, such as sensitivity to sunlight, near-sightedness, far-sightedness, or astigmatism (a curvature in the lens that makes it difficult to focus on objects). Other common affects of albinism on the eyes include nystagmus, a constant, involuntary shifting of the eyes from side to side; and strabismus, a disorder of the muscles in the eyes that causes a wandering eye or crossed eyes. Strabismus can interfere with depth perception.

Skin conditions

People with albinism burn easily in the sun. Since they have no pigmentation, or very little, they typically do not tan. Without adequate protection, they are more likely to develop skin cancer. Some people with albinism will have freckles, or large blotches of pigmentation, but they still will not develop a suntan.

Other rare symptoms

People with HPS may experience a variety of health problems related to their unique form of albinism. For example, HPS can cause scarring of the lungs, or fibrosis, which leads to restrictive lung disease and causes fatigue and problems with breathing. Some people with HPS have trouble healing when they cut their skin because the disorder interferes with normal platelet function. Platelets are a component of blood needed for clotting. This complication may cause people with HPS to bruise easily, have frequent nosebleeds or trouble with bleeding gums when brushing their teeth. It also could cause heavy menstrual bleeding and excessive bleeding when a pregnant woman with HPS delivers a child. Intestinal difficulties also are associated with HPS. It can cause a condition called granulomatous colitis, which causes abdominal cramps, intestinal bleeding and diarrhea. People with HPS may also have kidney disease. Other rare forms of albinism may cause deafness or decrease the body's ability to fight infection.

Diagnosis

Physicians are able to diagnose albinism by carefully examining a person's hair, skin, eyes, and family history. Diagnostic testing usually is not necessary, but a genetic test is now available for parents who want to find out if they are carriers of ty-neg albinism. The test also can be performed on an infant by amniocentesis at 16 to 18 weeks gestation.

In the past, doctors used to examine a sample of the root of a person's hair, in a procedure known as a hair-bulb pigmentation test. They also tested hair for the presence of tyrosine, a substance in the body that produces melanin, to determine the type of albinism a person had. Today, however, most physicians believe these tests are not reliable and they are not often used.

To find out if a person has HPS, physicians can take a sample of their blood and examine the platelets under a microscope to look for a lack of clotting ability.

Eye doctors may be able to identify subtle eye changes in women who carry the gene for X-linked ocular albinism. While their eye color may appear normal, female carriers of this type of albinism often have a slight lack of pigment in their retinas.

Treatment and management

People with albinism must shield their sensitive eyes from the sun with UV protected sunglasses. Some find bifocals and other corrective lenses to be helpful. For those with severe forms of albinism, however, corrective lenses may not be able to overcome problems caused by developmental changes in the retina. Children with albinism may require special accommodations, such as large-print textbooks, for reading in school. If visual impairment is severe, it may affect the individual's ability to drive.

For those with strabismus, surgery can alter their appearance, although the procedure may not significantly improve their vision. Before trying surgery, some doctors have children wear an eye patch in an attempt to strengthen the weaker eye. Eye surgery may also help reduce the involuntary eye movements associated with nystagmus, but vision will not always improve.

To prevent sun-related health problems, people with albinism must cover up with a sunscreen of SPF 20 or higher. Protective clothing, hats or visors are essential. Physicians also recommend keeping a careful watch for any changes in birth marks or moles that could become cancerous.

People with HPS should be careful to avoid aspirin, which can reduce clotting, and notify their dentist before having any dental work done. Women with HPS should alert their gynecologist or obstetrician. Some physicians recommend wearing a medical alert bracelet for the bleeding disorder. To avoid exacerbating the lung disease, people with HPS should not smoke.

Children with albinism may need extra support from family or a counselor if they are exposed to teasing or hurtful comments at school. Many families also find support groups to be helpful.

Prognosis

People with albinism can easily adapt to this condition and live healthy, productive lives. Albinism does not affect a person's lifespan, although it may lead to an increased risk of skin cancer if protective measures are not taken.

Resources

BOOKS

Larry. National Association for the Visually Handicapped, New York.

Wiley, Jean. To Ride the White Rainbow. National Organization for Albinism and Hypopigmentation (NOAH), 1998.

PERIODICALS

"NOAH News" Newsletter of the National Organization for Albinism and Hypopigmentation, Philadelphia.

Wilson, Tracy. "The paler side of beauty." Heart and Soul. Vol. 6, Issue 1 (February 1999): 30-33.

ORGANIZATIONS

American Academy of Dermatology. PO Box 4014, 930 N. Meacham Rd., Schaumburg, IL 60168-4014. (847) 330-0230. Fax: (847) 330-0050. <http://www.aad.org>.

American Council of the Blind. 1155 15th St. NW, Suite 1004, Washington, DC 20005. (202) 467-5081 or (800) 424-8666. <http://www.acb.org>.

American Nystagmus Network. PO Box 45, Jenison, MI 49429-0045. <http://www.nystagmus.org>.

Hermansky-Pudlak Syndrome Network. 39 Riveria Court, Malverne, NY 11565-1602. (800) 789-9477 or (516) 599-2077. <http://www.medhelp.org/web/hpsn.htm>.

International Albinism Center. University of Minnesota, PO Box 420, Delaware St. SE, Minneapolis, MN 55455. <http://www.cbc.umn.edu/iac>.

National Association for Parents of Children with Visual Impairment (NAPVI). PO Box 317, Watertown, MA 02472. (617) 972-7441 or (800) 562-6265. <http://www.spedex.com/napvi>.

National Organization for Albinism and Hypopigmentation. 1530 Locust St. #29, Philadelphia, PA 19102-4415. (215) 545-2322 or (800) 473-2310. <http://www.albinism.org>.

WEBSITES

"Images of albinism in pop culture." Lunaeterna. <http://www.lunaeterna.net/popcult/intro.htm>.

"International Albinism Center fact sheet." University of Minnesota.<http://www.cbc.umn.edu/iac/facts.htm>.

"Positive Exposure: Albinism and photography." <http://www.rickguidotti.com>.

OTHER

Albinism: The People, The Challenge. Videotape. Chrysalis Films.

Melissa Knopper

Albinism

Definition

Albinism is an inherited condition that causes a lack of pigment in the hair, skin or eyes.

Description

People with albinism typically have white or pale yellow hair, pale skin and light blue or gray eyes. Since their irises have little pigment, their eyes may appear pink or violet in different types of light. This is because light is being reflected from the reddish part of the retina

in the back of the eye. Their skin usually does not tan and their eyes are often sensitive to light. Many have trouble with vision. Some children may be born with albinism, but develop some pigmentation as they grow older.

In albinism, the body does not produce enough of a pigment called melanin, which creates hair, skin and eye color. Melanin protects the body by absorbing the sun's ultraviolet light. There are several types of albinism: some affect only the eyes, while others affect the skin and hair or other parts of the body.

Types of albinism

Ocular: A form of albinism that mainly affects the eyes. People with ocular albinism have some pigmentation, but may have lighter skin, hair and eye color than other family members. Scientists have identified five different types of ocular albinism.

X-linked ocular: This type of albinism occurs mostly in males, who inherit the gene from their mothers. It causes visual disabilities.

Oculocutaneous: A type of albinism that affects the hair, skin and eyes. Researchers have classified 10 different types of oculocutaneous albinism.

Tyrosinase-negative oculocutaneous: Also known as Type 1A, this is the most severe form of albinism, marked by a total absence of pigment in hair, skin and eyes. People with this type of albinism have vision problems and sensitivity to sunlight. They also are extremely susceptible to sunburn.

Tyrosinase-positive oculocutaneous: People with this type of albinism have light hair, skin and eye coloration and fewer visual impairments.

Hermansky-Pudlak syndrome (HPS): This rare type of albinism is common in the Puerto Rican community. Approximately one person in every 1,800 people in Puerto Rico will be affected by it. The lack of pigmentation can vary widely. People with HPS may have white, pale yellow or brown hair, but it always is lighter than the rest of the population. Their eyes range from blue to brown, and their skin can be creamy white, yellow or brown. HPS also often causes visual changes, along with other physical symptoms.

Chediak-Higashi syndrome : A rare type of albinism that interferes with white blood cells and the body's ability to fight infection.

Black Locks Albinism Deafness syndrome (BADS): Another rare form of albinism identified by a black lock of hair on the forehead. BADS causes deafness from birth.

Piebaldism: Also known as partial albinism, this condition is marked by patches of white hair or lighter skin blotches on the body.

Genetic profile

Children inherit the genes for albinism from their parents. The parents may have normal pigmentation, but if both the mother and father carry a recessive gene, there is a one in four chance their child will have albinism.

A specific genetic abnormality causes tyrosinasenegative oculocutaneous albinism (Type 1A). In this type, also called "ty-neg albinism," the body is unable to convert the amino acid tyrosine into pigment. The genes for producing the enzymes related to ty-neg albinism are located on chromosome 11 and chromosome 9.

Similarly, scientists believe the gene that causes Hermansky-Pudlak syndrome is on chromosome 10. They are studying two other genes that appear to be involved in melanin pigment formation: the P gene on chromosome 15 and the ocular albinism gene on the X chromosome.

Women who carry the gene for X-linked ocular albinism may have normal vision, but they have a one in two chance of passing it on to their sons. This type of albinism occurs mainly in males because the gene that causes it is located on the X chromosome. Since males only have one X chromosome, genetic abnormalities on this chromosome will almost always be expressed.

Demographics

Albinism affects one in every 17,000 people. All racial groups, including African-Americans and Latinos are affected by albinism. Asians have the lowest incidence of this condition.

Signs and symptoms

Eye problems

The lack of pigment in albinism causes abnormal development in the eye. For example, the iris (the colored ring around the center of the eye), which normally acts as a filter, may let too much light into the eye. Communication between the retina (the surface inside the eye that absorbs light) and the brain may also be altered in people with albinism, causing a lack of depth perception. These changes can lead to visual impairments, such as sensitivity to sunlight, near-sightedness, far-sightedness, or astigmatism (a curvature in the lens that makes it difficult to focus on objects). Other common affects of albinism on the eyes include nystagmus, a constant, involuntary shifting of the eyes from side to side; and strabismus, a disorder of the muscles in the eyes that causes a wandering eye or crossed eyes. Strabismus can interfere with depth perception.

Skin conditions

People with albinism burn easily in the sun. Since they have no pigmentation, or very little, they typically do not tan. Without adequate protection, they are more likely to develop skin cancer . Some people with albinism will have freckles, or large blotches of pigmentation, but they still will not develop a suntan.

Other rare symptoms

People with HPS may experience a variety of health problems related to their unique form of albinism. For example, HPS can cause scarring of the lungs, or fibrosis, which leads to restrictive lung disease and causes fatigue and problems with breathing. Some people with HPS have trouble healing when they cut their skin because the disorder interferes with normal platelet function. Platelets are a component of blood needed for clotting. This complication may cause people with HPS to bruise easily, have frequent nosebleeds or trouble with bleeding gums when brushing their teeth. It also could cause heavy menstrual bleeding and excessive bleeding when a pregnant woman with HPS delivers a child. Intestinal difficulties also are associated with HPS. It can cause a condition called granulomatous colitis, which causes abdominal cramps, intestinal bleeding and diarrhea. People with HPS may also have kidney disease.

Other rare forms of albinism may cause deafness or decrease the body's ability to fight infection.

Diagnosis

Physicians are able to diagnose albinism by carefully examining a person's hair, skin, eyes, and family history. Diagnostic testing usually is not necessary, but a genetic test is now available for parents who want to find out if they are carriers of ty-neg albinism. The test also can be performed on an infant by amniocentesis at 16 to 18 weeks gestation.

In the past, doctors used to examine a sample of the root of a person's hair, in a procedure known as a hairbulb pigmentation test. They also tested hair for the presence of tyrosine, a substance in the body that produces melanin, to determine the type of albinism a person had. Today, however, most physicians believe these tests are not reliable and they are not often used.

To find out if a person has HPS, physicians can take a sample of their blood and examine the platelets under a microscope to look for a lack of clotting ability.

Eye doctors may be able to identify subtle eye changes in women who carry the gene for X-linked ocular albinism. While their eye color may appear normal, female carriers of this type of albinism often have a slight lack of pigment in their retinas.

Treatment and management

People with albinism must shield their sensitive eyes from the sun with UV protected sunglasses. Some find bifocals and other corrective lenses to be helpful. For those with severe forms of albinism, however, corrective lenses may not be able to overcome problems caused by developmental changes in the retina. Children with albinism may require special accommodations, such as large-print textbooks, for reading in school. If visual impairment is severe, it may affect the individual's ability to drive.

For those with strabismus, surgery can alter their appearance, although the procedure may not significantly improve their vision. Before trying surgery, some doctors have children wear an eye patch in an attempt to strengthen the weaker eye. Eye surgery may also help reduce the involuntary eye movements associated with nystagmus, but vision will not always improve.

To prevent sun-related health problems, people with albinism must cover up with a sunscreen of SPF 20 or higher. Protective clothing, hats or visors are essential. Physicians also recommend keeping a careful watch for any changes in birth marks or moles that could become cancerous.

People with HPS should be careful to avoid aspirin, which can reduce clotting, and notify their dentist before having any dental work done. Women with HPS should alert their gynecologist or obstetrician. Some physicians recommend wearing a medical alert bracelet for the bleeding disorder. To avoid exacerbating the lung disease, people with HPS should not smoke.

Children with albinism may need extra support from family or a counselor if they are exposed to teasing or hurtful comments at school. Many families also find support groups to be helpful.

Prognosis

People with albinism can easily adapt to this condition and live healthy, productive lives. Albinism does not affect a person's lifespan, although it may lead to an increased risk of skin cancer if protective measures are not taken.

Resources

BOOKS

Larry. National Association for the Visually Handicapped, New York.

Wiley, Jean. To Ride the White Rainbow. National Organization for Albinism and Hypopigmentation (NOAH), 1998.

PERIODICALS

"NOAH News." Newsletter of the National Organization for Albinism and Hypopigmentation, Philadelphia.

Wilson, Tracy. "The paler side of beauty." Heart and Soul. Vol. 6, Issue 1 (February, 1999): 30-33.

ORGANIZATIONS

American Academy of Dermatology. PO Box 4014, 930 N. Meacham Rd., Schaumburg, IL 60168-4014. (847) 330-0230. Fax: (847) 330-0050. <http://www.aad.org>.

American Council of the Blind. 1155 15th St. NW, Suite 1004, Washington, DC 20005. (202) 467-5081 or (800) 424-8666. <http://www.acb.org>.

American Nystagmus Network. PO Box 45, Jenison, MI 49429-0045. <http://www.nystagmus.org>.

Hermansky-Pudlak Syndrome Network. 39 Riveria Court, Malverne, NY 11565-1602. (800) 789-9477 or (516) 599-2077. <http://www.medhelp.org/web/hpsn.htm>.

International Albinism Center. University of Minnesota, PO Box 420, Delaware St. SE, Minneapolis, MN 55455. <http://www.cbc.umn.edu/iac>.

National Association for Parents of Children with Visual Impairment (NAPVI). PO Box 317, Watertown, MA 02472. (617) 972-7441 or (800) 562-6265. <http://www.spedex.com/napvi>.

National Organization for Albinism and Hypopigmentation. 1530 Locust St. #29, Philadelphia, PA 19102-4415. (215) 545-2322 or (800) 473-2310. <http://www.albinism.org>.

WEBSITES

"Images of albinism in pop culture." Lunaeterna. <http://www.lunaeterna.net/popcult/intro.htm>.

"International Albinism Center fact sheet." University of Minnesota. <http://www.cbc.umn.edu/iac/facts.htm>.

"Positive Exposure: Albinism and photography." <http://www.rickguidotti.com>.

OTHER

Albinism: The People, The Challenge. Videotape. Chrysalis Films.

Melissa Knopper