EYA1

The EYA1 gene provides instructions for making a protein that plays a role in regulating the activity of other genes. Based on this role, the EYA1 protein is called a transcription factor or transcription coactivator.

The EYA1 protein interacts with several other proteins, including a group known as SIX proteins, to activate genes that are important for normal development. Before birth, these protein interactions appear to be essential for the normal formation of many tissues, including the second branchial arch (a structure that gives rise to tissues in the front and side of the neck) and the eyes, ears, and kidneys.

branchiootorenal syndrome - caused by mutations in the EYA1 gene

More than 100 mutations in the EYA1 gene have been identified in people with features of branchiootorenal (BOR) syndrome. Many of these mutations change the 3-dimensional structure of the EYA1 protein, which prevents it from interacting effectively with other proteins. Because these protein interactions are necessary for the activation of certain genes during embryonic development, the altered EYA1 protein disrupts the normal development of many tissues before birth. The major signs and symptoms of branchiootorenal syndrome result from abnormal development of the second branchial arch, ears, and kidneys.

EYA1 mutations have also been found in some people with a condition known as branchiooto (BO) syndrome. This condition includes many of the same features as branchiootorenal syndrome, but affected individuals do not have kidney (renal) malformations. The two conditions are otherwise so similar that researchers often consider them together (BOR/BO syndrome). It is unclear why some EYA1 mutations are associated with kidney malformations and others are not.

other disorders - caused by mutations in the EYA1 gene

Several mutations in the EYA1 gene have been associated with eye abnormalities including clouding of the lens (cataracts) and clouding of the clear front surface of the eye (the cornea). These abnormalities occur without the characteristic features of branchiootorenal syndrome. Researchers believe that the EYA1 mutations responsible for eye abnormalities are less severe than the mutations that underlie branchiootorenal syndrome, and these genetic changes likely affect different functions of the EYA1 protein.