Audiological findings in 100 USH2 patients

Area of Science:

• Genetics
• Audiology
• Ophthalmology

Background:

• Usher syndrome type II (USH2) is a genetic disorder characterized by bilateral sensorineural hearing loss (HL) and retinitis pigmentosa.
• HL in USH2 is typically mild to severe with a down-sloping audiometric configuration and is the earliest presenting symptom.
• Understanding the audiological characteristics is crucial for early diagnosis and management of USH2.

Purpose of the Study:

• To analyze audiological findings in a cohort of 100 Usher syndrome type II patients.
• To investigate potential correlations between specific gene mutations (USH2A, GPR98, DFNB31) and hearing loss characteristics.
• To determine if audiograms can predict the underlying genetic mutation in USH2.

Main Methods:

• Retrospective analysis of audiological data from 100 USH2 patients across 92 families.
• Classification of patients into groups based on the involved gene: USH2A (88), GPR98 (10), and DFNB31 (2).
• Detailed audiogram analysis including pure tone average, degree of hearing loss, and configuration.

Main Results:

• The median age of HL diagnosis was 5 years, with a median USH2 diagnosis age of 34.5 years.
• Moderate hearing loss (76%) and a gently down-sloping audiometric configuration (66%) were predominant findings.
• No statistically significant differences in audiograms were found between USH2A and GPR98 groups, though GPR98 patients showed a tendency towards severe hearing loss.

Conclusions:

• Audiological findings in USH2 patients are generally consistent, with moderate, down-sloping hearing loss being common.
• While a tendency for more severe hearing loss was observed in GPR98 patients, it is not possible to predict the specific mutated gene solely based on audiogram results.
• Further research may be needed to identify specific audiological markers for different USH2 genotypes.