oculocutaneous albinism


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Related to oculocutaneous albinism: Oculocutaneous albinism type 3, Oculocutaneous albinism type 2, Oculocutaneous albinism type 1

oc·u·lo·cu·ta·ne·ous al·bi·nism

a disorder characterized by deficiency of pigment in skin, hair, and eyes, photophobia, nystagmus, and decreased visual acuity; there are two types: tyrosinase negative [MIM*203100] in which there is absence of tyrosinase, and tyrosinase positive [MIM*203200] in which normal tyrosinase cannot enter pigment cells; the compound heterozygote is normal so the two forms are not allelic. There are several forms of autosomal recessive inheritance: type IA is characterized by absence of tyrosinase with life-long complete absence of melanin, marked photophobia, and nystagmus, caused by mutation in the tyrosinase gene (TYR) on chromosome 11q. Type II has normal tyrosinase activity and is the most common; hair color darkens and nevi and freckles develop; caused by mutation in the oculocutaneous abinism gene (OCA2) on 15q. Type III is characterized by absent tyrosinase but pigmentation of the iris in the first decade; caused by mutation in the tyrosine-related protein-1gene (TYRP1) on 9p. Type IV is found in Africans with normal tyrosinase and type V is associated with red hair. Type VI is synonymous to Hermansky-Pudlak syndrome [MIM*203300], with low to absent tyrosinase and hemorrhage due to platelet deficiency, caused by mutation in the Hermansky-Pudlak gene (HPS) on 10q.

oculocutaneous albinism (OCA)

[ok′yo̅o̅lōkyo̅o̅tā′- nē·əs]
a human albinism occurring in 10 types, all distinguished in their incidence and genetic, biochemical, and clinical characteristics but having in common varying degrees of decreased melanotic pigment of the skin, hair, and eyes; hypoplastic foveas; photophobia; nystagmus; and decreased visual acuity.

albinism 

Congenital anomaly due to a defect of melanin production as a result of one of several possible genetic defects. Oculocutaneous albinism type 1(OCA1) is due to a genetic defect in tyrosinase, the enzyme that metabolizes the amino acid tyrosine, which is essential for its conversion to melanin (formerly called tyrosinase-negative albinism). It is an autosomal recessive condition, which affects the skin, hair and eyes. The iris is a pale colour, the fundus and the pupil are reddish and the eye transilluminates markedly. There is poor visual acuity, photophobia, nystagmus and strabismus. Oculocutaneous type 2 (OCA2) is caused by a mutation of the OCA2 ('P') gene resulting in variable amounts of melanin synthesis. The hypopigmentation of the eyes, skin and hair varies from fair to normal (formerly called tyrosinase-positive albinism). It may be associated with the Hermansky-Pudlak syndrome in which there is albinism and easy bruising or bleeding. The other type of albinism is ocular albinism type 1 (OA1). It is inherited either as an X-linked or less commonly as an autosomal recessive trait. It affects mainly the eyes and in most instances males only and the skin colour is usually normal. Management involves full correction, possibly with tinted lenses. Surgery may be required for strabismus. See ocular fundus; inheritance; trans-illumination.
References in periodicals archive ?
Most importantly, direct quotations of the research participants were captured during data collection and analysis so as to reflect the true personal experiences of people with oculocutaneous albinism.
Focusing on the essence on oculocutaneous albinism, and points of significance to formulate ideas on the participants' life-experience.
It became clear during the data collection and analysis process that myths, superstitions and stigma are major challenges faced by people with oculocutaneous albinism.
Of the fifteen participants, fourteen felt very strongly that the onus is on the 'self-concept' of the persons with oculocutaneous albinism to improve their self-worth in the community.
but we must go out raise awareness on oculocutaneous albinism.
In line with Maslow's self-actualisation theory, it emerged in the findings of this research that the family and community play a fundamental role in enhancing the self-concept of people with oculocutaneous albinism.
This study revealed that families of people with oculocutaneous albinism and families without people with oculocutaneous albinism both have a social role to play in enhancing the self-esteem and in the development and growth of people with oculocutaneous albinism.
2002) emphasise that if rejection starts from birth, the chances are high that the person with oculocutaneous albinism will later succumb to the community's negative attitudes and stereotypes.
The findings reveal that the participants recognised the significant role of the external environment, especially the community, in enhancing the 'self-concept' of people with oculocutaneous albinism.
In line with most previous studies (Gaigher et al 2002; Kromberg 1992; Pooe-Monyemore 2003), stigma and prejudice in the community emerged as a major challenge faced by most people with oculocutaneous albinism.
2002) argue that the problems experienced by persons with oculocutaneous albinism do not necessarily relate to their obvious physical difference in terms of skin colour, but to the social environment that they have to cope with, which is also influenced by myths and superstitions in the community.
It emerged clearly in this study that myths and superstitions about oculocutaneous albinism affected the participants' everyday social life and self-image.

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