Albinism is a rare group of genetic disorders that cause the
skin, hair, or eyes to have little or no color. Albinism is also associated
with vision problems. According to the National
Organization for Albinism and Hypopigmentation, about 1 in 18,000 to 20,000
people in the United States has a form of albinism.
Different gene defects characterize the numerous types of
albinism. Types of albinism include:
Oculocutaneous Albinism (OCA)
OCA affects the skin, hair, and eyes. There are several subtypes
OCA1 is due to a defect in the tyrosinase enzyme. There are two
subtypes of OCA1.
- OCA1a: People with OCA1a have a complete absence
of melanin, the pigment that gives skin, eyes, and hair their coloring. People
with this subtype have white hair, very pale skin, and light eyes.
- OCA1b: People with OCA1b produce some melanin.
They have light-colored skin, hair, and eyes. Their coloring may increase as
OCA2 is less severe than OCA1. It’s due to a defect in the OCA2
gene that results in reduced melanin production. People with OCA2 are born with
light coloring and skin, and their hair may be yellow, blond, or light brown.
OCA2 is most common in Sub-Saharan Africans, African Americans, and Native Americans.
OCA3 is a defect in the TYRP1 gene. It usually affects
dark-skinned people, particularly black South Africans. People with OCA3 have
reddish-brown skin, reddish hair, and hazel or brown eyes.
OCA4 is due to a defect in the SLC45A2 protein. It results in a
minimal production of melanin and commonly appears in people of East Asian
descent. People with OCA4 have symptoms similar to those in people with OCA2.
Ocular Albinism (OA)
OA is the result of a gene mutation on the X chromosome and occurs
almost exclusively in males. This type of albinism only affects the eyes.
People with OA have normal hair, skin, and eye coloring, but have no coloring
in the retina (the back of the eye).
Hermansky-Pudlak Syndrome (HPS)
HPS is a rare form of albinism that is due to a defect in one of
eight genes. It produces symptoms similar to OCA, and occurs with lung, bowel,
and bleeding disorders.
Chediak-Higashi syndrome is another rare form of albinism that is
the result of a defect in the LYST gene. It produces symptoms similar to OCA,
but may not affect all areas of the skin. Hair is usually brown or blond with a
silvery sheen, and the skin is usually creamy white to grayish. People with
Chediak-Higashi syndrome have a defect in the white blood cells, increasing
their risk of infections.
Griscelli Syndrome (GS)
GS is an extremely rare genetic disorder. It’s due to a defect in
one of three genes. There only have been 60 known cases of GS worldwide since
1978. GS occurs with albinism (but may not affect the entire body), immune
problems, and neurological problems. GS usually results in death within the
first decade of life.
A defect in one of several genes that produce or distribute
melanin causes albinism. The defect may result in the absence of melanin
production, or a reduced amount of melanin production. The defective gene
passes down from both parents to the child and causes albinism.
Albinism is an inherited disorder that’s present at birth.
Children are at risk of being born with albinism if they have parents with
albinism, or parents who carry the gene for 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,
- 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
The most accurate way to diagnose albinism is through genetic
testing to detect defective genes related to albinism. Less accurate ways of
detecting albinism include an evaluation of symptoms by your doctor or an
electroretinogram test. This test measures the response of the light-sensitive
cells in the eyes to reveal eye problems associated with albinism.
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
- surgery on the muscles of the eyes to correct
abnormal eye movements
Most forms of albinism don’t affect lifespan. Hermansky-Pudlak
syndrome, Chediak-Higashi syndrome, and Griscelli syndrome do affect lifespan
because of the health problems associated with the syndromes.
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.