TECTA

The TECTA gene provides instructions for making a protein called alpha-tectorin. This protein is found in the inner ear, as part of a structure called the tectorial membrane. The tectorial membrane helps to convert sound waves to nerve impulses, a critical process for normal hearing.

Alpha-tectorin interacts with other proteins to form the tectorial membrane. Two regions of the alpha-tectorin protein, called the vWFD domain and the zona pellucida domain, are important for protein interactions and assembly of the tectorial membrane.

nonsyndromic deafness - caused by mutations in the TECTA gene

Researchers have identified several TECTA mutations that cause a form of nonsyndromic deafness (hearing loss without related signs and symptoms affecting other parts of the body) called DFNA8/A12. DFNA8/A12 deafness is inherited in an autosomal dominant manner, which means that one copy of an altered TECTA gene in each cell is sufficient to cause hearing loss. TECTA mutations replace one of the protein building blocks (amino acids) used to make alpha-tectorin with an incorrect amino acid. TECTA mutations affect the vWFD domain or the zona pellucida domain, which are important regions for interactions with other proteins. If the amino acid replacement alters normal protein interactions, it could disrupt the structure of the tectorial membrane and the conversion of sound to nerve impulses.

Researchers have also identified a few TECTA mutations that cause a form of nonsyndromic deafness called DFNB21. DFNB21 deafness is inherited in an autosomal recessive manner, which means two copies of the TECTA gene in each cell are altered. These TECTA mutations create a premature stop signal in the instructions for making the alpha-tectorin protein. Although the effect of these mutations is not fully understood, most likely no protein is produced or an abnormally small protein is made. A missing or abnormally small alpha-tectorin protein would disrupt the structure of the tectorial membrane and the conversion of sound to nerve impulses.