Cochleovestibular and ocular features in a Dutch DFNA11 family

Abstract

Objectives: To report hearing impairment and vestibular and ocular features in a Dutch DFNA11 family and to compare these results to reported data on three other DFNA11 families.

Study design: Family study.

Methods: Regression analysis was performed in relation to age to outline the development of hearing thresholds and speech recognition scores. Vestibular and ocular functions were examined.

Results: First symptoms of hearing impairment started between the ages of 4 and 43 years. Most of the audiograms were symmetric and flat or downsloping. The annual threshold deterioration increased from 0.2 to 2.6 dB per year at 0.25 to 8 kHz in the longitudinal analyses and in the cross-sectional analysis from 0.3 to 0.9 dB per year. The speech recognition score was quite good, deteriorating by 0.9% per year from a 90% score at the age of 36 years onward. Remarkably, extensive ocular examination including corrected visual acuity and refraction measurements, slit-lamp examination, ophthalmoscopy, Goldmann perimetry, electroretinography and electro-oculography revealed signs of subclinical retinal dysfunction. None of the patients showed the classic triad of retinitis pigmentosa. Pure-tone thresholds, phoneme recognition scores, and vestibular responses of the mutation carriers were fairly similar to previously described DFNA11 families.

Conclusion: Even though the diverse mutations are located in different regions of the myosin VIIa gene, the cochleovestibular phenotype is fairly similar in all DFNA11 families. Surprisingly, only in this family was subclinical retinal dysfunction detected.