Sensorineural hearing loss and Mondini dysplasia caused by a deletion at locus DFN3.

OBJECTIVE To study a family with inner ear malformations and sensorineural hearing loss. DESIGN Clinical, radiological, and genetic study of the members of a family with different degrees of sensorineural hearing loss. RESULTS The males in the family manifested profound congenital hearing loss with severe inner ear malformations, while the only affected female had progressive hearing loss that had begun during puberty. Computed tomography showed inner ear malformations in both males, with enlarged internal auditory meatus and Mondini dysplasia. Genetic analysis disclosed a microdeletion at the locus DFN3 on chromosome X. CONCLUSION A familial Mondini dysplasia is associated to a microdeletion at the deafness locus DFN3.