Types of albinism
To date, there are several identified types of albinism. Below you will find a brief description of each:
Ocular Albinism (OA) affects only the eyes, not the skin or hair. It results from an X-linked chromosomal inheritance and so occurs mostly in boys.
Oculocutaneous Albinism (OCA) affects the eyes, hair and skin and includes several different forms. The first form, OCA1 involves the tyrosinase enzyme, which converts tyrosine (an amino acid) into melanin. Melanin is a chemical that colors our skin, eyes and hair. OCA1 includes two sub-groups:
Hermansky-Pudlak Syndrome (HPS) is a rare type of albinism, which has an increased incidence among people of Puerto Rican descent. It may involve bleeding disorders, bruising, lung problems and intestinal disorders.
Chediak-Higashi Syndrome is another rare form of albinism. It is characterized by an abnormality in certain types of white blood cells, lowering resistance to infection. .
Griscelli Syndrome is an extremely rare type of albinism. In fact, there are only 60 known cases worldwide. Like Chediak-Higashi Syndrome, it involves immunodeficiency and may also have associated neurological problems.
Ocular Albinism (OA) affects only the eyes, not the skin or hair. It results from an X-linked chromosomal inheritance and so occurs mostly in boys.
Oculocutaneous Albinism (OCA) affects the eyes, hair and skin and includes several different forms. The first form, OCA1 involves the tyrosinase enzyme, which converts tyrosine (an amino acid) into melanin. Melanin is a chemical that colors our skin, eyes and hair. OCA1 includes two sub-groups:
- OCA1a: Those with this type of albinism have no pigment and no active tyrosinase
- OCA1b: Those with this type of albinism have some residual tyrosinase activity and so havesome pigment. Although they have decreased pigmentation at birth, it may increase slightly throughout their lives. People in this group may even have the ability to sun tan.
Hermansky-Pudlak Syndrome (HPS) is a rare type of albinism, which has an increased incidence among people of Puerto Rican descent. It may involve bleeding disorders, bruising, lung problems and intestinal disorders.
Chediak-Higashi Syndrome is another rare form of albinism. It is characterized by an abnormality in certain types of white blood cells, lowering resistance to infection. .
Griscelli Syndrome is an extremely rare type of albinism. In fact, there are only 60 known cases worldwide. Like Chediak-Higashi Syndrome, it involves immunodeficiency and may also have associated neurological problems.