Tietz syndrome

Tietz syndrome is a rare genetic disorder characterized by profound hearing loss from birth and unusually light-colored skin and hair.

Overview

Tietz syndrome is characterized by profound hearing loss and hypopigmentation. The hearing loss is caused by abnormalities of the inner ear (sensorineural hearing loss) and is present from birth. While affected individuals are born with white hair and very pale skin, hair color often changes to blond or light red over time. They sunburn easily but may tan slightly or develop reddish freckles.

Eye Health

The condition also affects the eyes. The iris is typically blue or gray. Specialized cells in the eye called retinal pigment epithelial cells lack their normal pigment, which can be detected during an eye examination. Some individuals may experience mild vision problems.

Causes

Tietz syndrome is caused by pathogenic variants in the MITF gene. This gene provides instructions for making a protein that acts as a transcription factor, playing a major role in the development and function of melanocytes (pigment-producing cells). These cells are essential for skin, hair, and eye color, as well as for proper hearing in the inner ear. The altered protein produced in Tietz syndrome impairs the development of melanocytes and the production of melanin.

Inheritance

This condition is inherited in an autosomal dominant pattern, meaning one copy of the altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person has one parent who also has the condition.