Ocular albinism
Encyclopedia
Ocular albinism is a form of albinism
which, in contrast to oculocutaneous albinism
, presents primarily in the eye
s. There are multiple forms of ocular albinism, which are clinically similar.
Both known genes are on the X chromosome
. When the term "autosomal recessive ocular albinism" ("AROA") is used, it usually refers to mild variants of oculocutaneous albinism.
Albinism
Albinism is a congenital disorder characterized by the complete or partial absence of pigment in the skin, hair and eyes due to absence or defect of an enzyme involved in the production of melanin...
which, in contrast to oculocutaneous albinism
Oculocutaneous albinism
Oculocutaneous albinism is a form of albinism involving the eyes , skin , and in rare instances, the hair as well.Four types of oculocutaneous albinism have been described, all caused by a disruption of melanin synthesis and all autosomal recessive disorders.Common Albinism requires genes from both...
, presents primarily in the eye
Human eye
The human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...
s. There are multiple forms of ocular albinism, which are clinically similar.
Both known genes are on the X chromosome
X chromosome
The X chromosome is one of the two sex-determining chromosomes in many animal species, including mammals and is common in both males and females. It is a part of the XY sex-determination system and X0 sex-determination system...
. When the term "autosomal recessive ocular albinism" ("AROA") is used, it usually refers to mild variants of oculocutaneous albinism.
Types
| Name | OMIM | Gene | Description >- | Ocular albinism, type 1 (OA1) |
GPR143 GPR143 G-protein coupled receptor 143 is a protein that in humans is encoded by the GPR143 gene.Ocular albinism type 1 protein is a conserved integral membrane protein with seven transmembrane domains... |
>- | CACNA1F | color blindness Color blindness Color blindness or color vision deficiency is the inability or decreased ability to see color, or perceive color differences, under lighting conditions when color vision is not normally impaired... ) and with night blindness (nyctalopia Nyctalopia Nyctalopia is a condition making it difficult or impossible to see in relatively low light. It is a symptom of several eye diseases. Night blindness may exist from birth, or be caused by injury or malnutrition... ). >- | Ocular albinism with sensorineural deafness (OASD) |
? (Xp22.3) | Is, as its name implies, associated with loss of hearing. May be the same as OA1. |