OTX2

The OTX2 gene provides instructions for producing a protein that regulates the activity of other genes. On the basis of this action, the OTX2 protein is called a transcription factor. The OTX2 gene is part of a family of homeobox genes, which act during early embryonic development to control the formation of many body structures.

The OTX2 gene plays a critical role in the development of the eyes and related structures, such as the nerves that carry visual information from the eyes to the brain (optic nerves). It is also involved in brain development, including the formation of the pituitary gland at the base of the brain. The pituitary gland produces hormones that help control growth, reproduction, and other critical body functions.

septo-optic dysplasia - caused by mutations in the OTX2 gene

At least eight mutations in the OTX2 gene have been identified in people with the major features of septo-optic dysplasia. Some of these mutations prevent the production of a functional OTX2 protein. Other mutations lead to a defective version of the protein that cannot regulate the activity of other genes.

A shortage of the OTX2 protein disrupts the formation and early development of the eyes, the optic nerves, the pituitary gland, and other brain structures. These problems with development lead to the major features of septo-optic dysplasia, including eye abnormalities, underdevelopment of the pituitary gland (pituitary hypoplasia), and learning difficulties. However, the signs and symptoms associated with OTX2 gene mutations vary widely, even among affected members of the same family. Additional features that have been reported in people with OTX2 gene mutations include delayed development, slow growth, and seizures.

Studies suggest that mutations in the OTX2 gene are a rare cause of septo-optic dysplasia.

Genetics Home Reference provides information about these additional conditions, which are also associated with changes in the OTX2 gene:

• coloboma
• combined pituitary hormone deficiency
• microphthalmia