Causes

Several genes provide instructions for making one of several proteins involved in the production of melanin. Melanin is produced by cells called melanocytes, which are found in your skin, hair and eyes.

Albinism is caused by a mutation in one of these genes. Different types of albinism can occur, based mainly on which gene mutation caused the disorder. The mutation may result in no melanin at all or a significantly reduced amount of melanin.

Types of albinism

Types of albinism are classified based on how they're inherited and on the gene that is affected.

• Oculocutaneous albinism (OCA), the most common type, means a person inherited two copies of a mutated gene — one from each parent (autosomal recessive inheritance). It's the result of a mutation in one of seven genes, labeled from OCA1 to OCA7. OCA causes decreased pigment in the skin, hair and eyes, as well as vision problems. The amount of pigment varies by type, and the resulting color of skin, hair and eyes also varies by and within types.
• Ocular albinism is mainly limited to the eyes, causing vision problems. The most common form is type 1, inherited by a gene mutation on the X chromosome. X-linked ocular albinism can be passed on by a mother who carries one mutated X gene to her son (X-linked recessive inheritance). Ocular albinism occurs almost exclusively in males and is much less common than OCA.
• Albinism related to rare hereditary syndromes can occur. For example, Hermansky-Pudlak syndrome includes a form of OCA as well as bleeding and bruising problems and lung and bowel diseases. Chediak-Higashi syndrome includes a form of OCA as well as immune problems with recurrent infections, neurologic abnormalities and other serious issues.