Albinism is an inherited genetic condition that reduces the amount of melanin pigment formed in the skin hair and eyes. Albinism occurs in all racial and ethnic groups throughout the world
Albinism occurs when one of several genetic defects makes the body unable to produce or distribute melanin.
These defects may be passed down (inherited) through families.
The most severe form of albinism is called oculocutaneous albinism (OCA). People with this type of albinism have white or pink hair, skin, and iris color. They also have vision problems.
Another type of albinism, called ocular albinism type 1 (OA1), affects only the eyes. The person’s skin and eye color are usually in the normal range. However, an eye exam will show that there is no coloring in the back of the eye (retina).
Hermansky-Pudlak syndrome (HPS) is a form of albinism caused by a change to a single gene. It can occur with a bleeding disorder, as well as with lung and bowel diseases.
Who Does It Affect?
The condition generally affects both sexes equally, although there is one type – known as ocular albinism (which mainly affects the eyes) – that is more common in males.
Albinism can affect people of all ethnic groups.
How Can Albinism Be Inherited?
In most cases, including all types of OCA and some types of OA, albinism is passed on in what is known as an autosomal recessive inheritance pattern.
However, some types of OA are caused by a mutation on the X chromosome (one of the sex chromosomes). This is known as an X-linked inheritance pattern.
Autosomal Recessive Inheritance
An autosomal recessive condition means you need to inherit two copies of the faulty gene (one from your mother and one from your father) to have the condition.
It is estimated that about one in 70 people carry the faulty gene that causes OCA. Carriers of the gene are not affected by the condition and have a normal amount of melanin.
If both parents carry the gene, there is a one in four chance that their child will have albinism and a one in two chance they will be a carrier.
X-linked recessive conditions often don’t affect females because females have two X chromosomes, one of which will be normal and can usually compensate for the mutated chromosome. However, females who inherit the mutation will become carriers.
If a male inherits the mutation from his mother (males receive a Y chromosome from their fathers), he will not have a normal copy of the gene and will develop albinism.
When a mother is a carrier of an X-linked mutation, each daughter they have has a one in two chance of becoming a carrier and each son they have has a one in two chance of having albinism.
When a father has an X-linked condition, his daughters will become carriers of the mutation.
What Are the Symptoms of Albinism?
People with albinism will have the following symptoms:
- an absence of color in the hair, skin, or eyes
- lighter than normal coloring of the hair, skin, or eyes
- patches of skin that have an absence of color
Albinism occurs with vision problems, which may include:
- Strabismus (crossed eyes)
- Photophobia (sensitivity to light)
- Nystagmus (involuntary rapid eye movements)
- Impaired vision or blindness
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.
There is no cure for albinism. Treatment for albinism can relieve symptoms and prevent sun damage. Treatment may include:
- Sunglasses to protect the eyes from UV rays
- Protective clothing and sunscreen to protect the skin from UV rays
- Prescription eyeglasses to correct vision problems
- Surgery on the muscles of the eyes to correct abnormal eye movements
What Is The Long-Term Outlook?
Most forms of albinism don’t affect lifespan.
People with albinism may have to limit their outdoor activities because their skin and eyes are sensitive to the sun. Ultraviolet rays from the sun can cause skin cancer and vision loss in some people with albinism.