Objective: To analyze the genetic causes of low frequency neuropathic hearing impairment.
Methods: Using the network established by our institute, the proband of the low frequency neuropathic hearing loss pedigree was found. Then, investigation was carried out in the family from the proband. Cyrillic 2.1 software was set up to draw the pedigree and genetic characterization and phenotypes were analyzed in this family.
Results: One-hundred and one alive family members were investigated and the clinic audiologic examinations were performed in 43 of 101 individuals. Six of forty-three individuals appeared to be low frequency neuropathic hearing loss and all patients were males without systemic disorders except hearing loss. The clinic phenotypes were mild, middle, severe and profound hearing loss with disappearing of the auditory brainstem response(ABR) and partial normal results of distortion product otoacoustic emission (DPOAE) in the affected individuals. The onset of hearing loss was at 10-16 years old and the age of all patients was arranged from 18 to 26 years old.
Conclusion: A large five generations family with hereditary low frequency neuropathic hearing impairment was found in our study. The genetic pattern in this family is male dominant X-linked recessive (XR) nonsyndromic hearing loss. Our findings suggest that some low frequency neuropathic disorders might be attributed to genetic factors.