WHRN
The WHRN gene, which encodes a protein called whirlin, is a key player in the intricate architecture of our sensory cells. Whirlin acts as a scaffolding protein, helping to organize and maintain the specialized structures within these cells that are essential for hearing and vision.
Whirlin‘s Role in Sensory Cells
Whirlin is primarily found in two crucial sensory organs:
- Inner Ear: Within the inner ear‘s cochlea, whirlin plays a vital role in the development and maintenance of stereocilia, the tiny hair-like projections on hair cells that detect sound vibrations. Whirlin helps anchor these stereocilia to the cell membrane, ensuring their proper alignment and organization.
- Retina: In the retina, the light-sensitive tissue at the back of the eye, whirlin is involved in the organization of photoreceptor cells (rods and cones) and their connecting neurons. It helps maintain the structural integrity of the retina and its ability to transmit visual signals to the brain.
WHRN Mutations and Associated Conditions
Mutations in the WHRN gene can disrupt whirlin‘s function, leading to various sensory impairments:
- Usher Syndrome Type II: This inherited disorder is characterized by hearing loss from birth and progressive vision loss due to retinitis pigmentosa. WHRN mutations are a major cause of Usher syndrome type II.
- Non-Syndromic Deafness (DFNB31): Some individuals with WHRN mutations experience hearing loss without any other associated symptoms, a condition known as DFNB31.
The Impact of WHRN Mutations
When whirlin is dysfunctional due to genetic mutations, the following can occur:
- Disrupted Stereocilia Development: In the inner ear, abnormal stereocilia development leads to hearing loss.
- Retinal Degeneration: In the retina, the disorganization of photoreceptor cells and their connections can result in progressive vision loss.