Thursday, September 12, 2019
Oculocutaneous Albinism Literature review Example | Topics and Well Written Essays - 1000 words
Oculocutaneous Albinism - Literature review Example Albinism is a typical hereditary skin disease with varied clinical presentation and inheritance. It is mostly present from birth and increases the risk of cancer. It is not curable and there is no specific treatment. It can be a part of syndromes which cause bleeding diathesis and recurrent infections (Okulicz, 2002). In this article, a specific type of albinism, the oculocutaneous type will be discussed. Albinism Albinism is a group of disorders that are hereditary in nature and are related to abnormality in the synthesis or distribution of melanin (Okulicz, 2002). The abnormality of pigmentation manifests in eyes with or without involvement of skin and hair (Park et al, 2012). Thus, clinically, there are 2 categories of albinism. They are ocular albinism where in eyes are involved and skin involvement is either absent or minimal, and oculocutaneous albinism in which skin and eyes are involved. Oculocutaneous albinism may be defined as "a group of congenital heterogeneous disorders in which there is either complete or partial absence of pigment in the skin, hair and eyes because of the absence of or a defect in an enzyme involved in the production of melanin" (Park et al, 2011). In both the conditions, the primary morbidity is related to the eye. The pattern of inheritance in albinism is variable. While the ocular albinism is through autosomal recessive or sex-linked inheritance, oculo-cutaneous albinism is autosomal recessive (Park et al, 2012). ... In patients with Hermansky-Pudlak syndrome, easy bruising is seen and in those with Chediak-Higashi syndrome, recurrent infections are noted. In X-linked ocular albinism, decreased hearing is seen (Okulicz, 2002). As far as discoloration of eyes, skin and hair is concerned, the range of depigmentation is variable and depends on the type of albinism. The color of the iris is usually blue and can even be brown. The iris will have transillumination defects. The fundus also, in general, is hypopigmented. To broadly classify, there are 2 forms of albinism. The classification is based on the tyrosinase hair bulb incubation test which differentiates between the tyrosinase-positive and tyrosinase-negative forms. In those who are tyrosinase-positive, some degree of production of pigments occurs. In those who are tyrosinase-negative, there is absolutely no pigment production (Okulicz, 2002). Oculocutaneous albinism There are four types of oculocutaneous albinism or OCA (Okulicz, 2002). OCA typ e 1A is the classic tyrosinase negative type of OCA. In this condition, the infant is born with blue-grey irides, pink colored skin, white hair and predominant red reflex (Wei et al, 2011). The individuals have manifestations of the defects of eye as discussed above. They never develop pigmented lesions like freckles, naevi or lentigines. Hair becomes yellow with age due to denaturation of the keratin following exposure to ultraviolet light. In type1B, the presentation features at birth are similar to those in type 1A. However, as the age advances, the hair color darkens to brown color. The skin can get tanned on exposure to sunlight and can even develop pigmented lesions like naevi and freckles. The
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