CLDN14

The CLDN14 gene provides instructions for making a protein called claudin 14. This protein is a member of the claudin protein family, which provides building components for tight junctions. Tight junctions seal the space between cells, creating a barrier that restricts the passage of fluids and certain particles in and out of cells. For example, tight junctions prevent digestive enzymes in intestinal cells from leaking into the blood.

Claudin 14 is found in the liver, kidneys, and inner ear, but its exact function is unclear. In the inner ear, this protein probably plays a role in converting sound waves to nerve impulses, a critical process for normal hearing. This conversion process requires the proper level of charged atoms (ions). Researchers suggest that tight junctions composed of claudin 14 help to maintain these ion levels.

nonsyndromic deafness - caused by mutations in the CLDN14 gene

Researchers have identified a few CLDN14 mutations that cause a form of nonsyndromic deafness (hearing loss without related signs and symptoms affecting other parts of the body) called DFNB29. One mutation deletes a single DNA building block (base pair), which disrupts the instructions for producing claudin 14. The remaining mutations change one of the protein building blocks (amino acids) used to make claudin 14. These changes probably alter the structure of claudin 14, which could impair the protein's ability to form tight junctions. Improper ion levels may result from missing or altered tight junctions, which could disrupt processes required for normal hearing.