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     Pigmentary Disorders:

 

Oculocutaneous Albinism

Oculocutaneous albinism (OCA) is a heterogeneous group of congenital disorders characterized by hypopigmentation of skin, hair, and eyes associated with other developmental ocular defects. OCA patients are often considered as legally blind and in India, it is one of the 4 major causes of childhood blindness. Long-term sun exposure greatly increases the risk of skin damage and an aggressive form of skin cancer called melanoma, in people with this condition. Mutations in genes regulating the multistep process of melanin biosynthesis cause this spectrum of disorders. The four classical types of oculocutaneous albinism are designated as OCA1 (OCA1A: MIM: 203100and OCA1B: MIM: 606952), OCA2 ( MIM: 203200), OCA3 ( MIM: 203290) and OCA4 ( MIM: 606574) caused by TYR, OCA2, TYRP1 and SLC45A2 genes, respectively. OCA1 is characterized by white hair, very pale skin, and light-colored irises. OCA2 and OCA4 have overlapping clinical features (a creamy white color and hair may be light yellow, blond, or light brown) that are generally less severe than OCA1. OCA3 affected individuals have reddish-brown skin, ginger or red hair and hazel or brown irises with milder vision abnormalities than the other forms of OCA. Overall, an estimated 1 in 20,000-30,000 people worldwide are born with oculocutaneous albinism however, the frequency differs from country to country. In India, OCA1 is the most prevalent type of OCA followed by OCA2.

            This database presently holds the relevant data for OCA1, OCA2 and OCA4 only.