Ocular albinism is a genetic condition that primarily affects the eyes. This condition reduces the coloring (pigmentation) of the iris, which is the colored part of the eye, and the retina, which is the light-sensitive tissue at the back of the eye. Pigmentation in the eye is essential for normal vision.

Ocular albinism type 1 results from mutations in the GPR143 gene. This gene provides instructions for making a protein that plays a role in pigmentation of the eyes and skin. It helps control the growth of melanosomes, which are cellular structures that produce and store a pigment called melanin. Melanin is the substance that gives skin, hair, and eyes their color. In the retina, this pigment also plays a role in normal vision.

The most common form of this disorder, ocular albinism type 1, affects at least 1 in 60,000 males. The classic signs and symptoms of this condition are much less common in females.

Ocular albinism type 1 is inherited in an X-linked pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the GPR143 gene in each cell is sufficient to cause the characteristic features of ocular albinism. Because females have two copies of the X chromosome, women with only one copy of a GPR143 mutation in each cell usually do not experience vision loss or other significant eye abnormalities. They may have mild changes in retinal pigmentation that can be detected during an eye examination.

Published Date: November 01, 2017
Published By: National Institutes of Health