CDH23 (Cadherin 23) encodes a member of the cadherin superfamily of calcium-dependent cell adhesion molecules. CDH23 is essential for mechanotransduction in inner ear hair cells and is associated with Usher syndrome type 1D, the most common form of syndromic deafness-blindness.
| Property |
Value |
| Gene Symbol |
CDH23 |
| Full Name |
Cadherin 23 |
| Chromosome |
10q22.1 |
| NCBI Gene ID |
64061 |
| Ensembl ID |
ENSG00000107736 |
| UniProt ID |
Q9Y6M7 |
| Protein Name |
Cadherin-23 |
| Associated Diseases |
Usher syndrome type 1D, sensorineural hearing loss, retinitis pigmentosa |
CDH23 encodes a large cadherin protein:
- Domain structure: Multiple extracellular cadherin repeats (EC repeats), transmembrane domain
- Calcium binding: Calcium ions between EC repeats stabilize the structure
- Dimerization: Forms cis-homodimers and trans-dimers with other cadherins
- Molecular size: Large protein (~3,654 amino acids)
In inner ear hair cells, CDH23 is critical for:
- Tip links: Forms the upper portion of tip link filaments
- Mechanotransduction: Tension on tip links opens mechanosensitive channels
- Stereocilia organization: Maintains proper organization of stereocilia bundles
- Hair bundle polarity: Essential for development of planar cell polarity
CDH23 is expressed in photoreceptors:
- Photoreceptor connecting cilia: Located in the connecting cilium
- Protein transport: May function in transport between inner and outer segments
- Photoreceptor maintenance: Essential for photoreceptor survival
- Inheritance: Autosomal recessive
- Clinical features: Congenital profound hearing loss, vestibular dysfunction, progressive retinitis pigmentosa
- Mechanism: Loss-of-function mutations cause complete loss of CDH23 function
- Diagnosis: Genetic testing confirms diagnosis
- DFNB12: Autosomal recessive nonsyndromic hearing loss
- Variants: Hypomorphic mutations cause milder phenotype
- Audiogram: Profound hearing loss across all frequencies
- Progressive degeneration: Photoreceptor degeneration leads to tunnel vision
- Night blindness: Initial symptom
- Therapeutic approaches: Gene therapy under development
CDH23 shows tissue-specific expression:
- Inner ear: Exclusively in hair cells of cochlea and vestibular organs
- Retina: Photoreceptor cells, specifically in the connecting cilium
- Pineal gland: Detected in pinealocytes
- Brain: Low expression in some brain regions
| Interactor |
Type |
Function |
| PCDH15 |
Cadherin |
Forms tip link with CDH23 |
| USH1C |
Scaffold |
Anchoring complex |
| Myosin VIIA |
Motor |
Intracellular transport |
| Whirlin |
Scaffold |
Stereocilia elongation |
- AAV vectors: Adeno-associated virus delivery of functional CDH23
- CRISPR/Cas9: Gene editing approaches for specific mutations
- Animal models: Mouse models for therapeutic testing
- Protein structure: Cryo-EM studies of tip link structure
- Regeneration: Hair cell regeneration strategies
- Biomarkers: CDH23 expression as disease marker