International Mammalian Genome Society

The 15th International Mouse Genome Conference (2001)

Table of Contents * Complex Genetics * Developmental Genetics * Gene Annotation * Gene Discovery * Genome Sequencing * Functional Genomics * Mutagenesis * Presentations * Verne Chapman Memorial Lecture

Dr. Konrad Noben-Trauth
NIDCD/NIH
5 Research Court
Rockville
MD 20850
USA

Co-Authors: Federica Di Palma, Richard Pellegrino
Institutions: Section on Neurogenetics, National Institute on Deafness & other Communication Disorders

Cadherins comprise a large family of transmembrane proteins, which are crucial for basic cellular processes such as cell-cell adhesion, cell sorting, and cell migration. Loss-of-function studies implicated cadherins in gastrulation, pattern formation and carcinogenesis. Recently, Cadherins were also shown to play critical roles during the development of the mammalian inner ear. Mutations in Cadherin 23 (Cdh23) and Protocadherin 15 (Pcdh15) cause deafness in waltzer (Cdh23v) and ames waltzer (Pcdh15av) mice respectively. In four alleles of waltzer (Cdh23v), loss-of-function mutations cause the disruption of the highly organized stereocilia bundle of hair cells in cochlea and vestibule during late embryonic/early postnatal development. The stereocilia disorganization and the restricted expression pattern suggest that Otocadherin may be involved in structuring the hair bundle. Mutations in the human homologue, CDH23, cause Usher syndrome type 1D, a recessive syndromic disorder characterized by congenital sensorineural hearing loss, retinitis pigmentosa and vestibular dysfunction. Hypomorphic alleles of Cdh23 were suggested to underlie the age-dependent hearing loss seen in many common inbred strains.

We report the complete genomic structure of Cdh23, describe alleles in normal and mutant strains and discuss Cdh23 as candidate for age-related hearing loss in mouse and man.