Speech Recognition Scores Related to Age and Degree of Hearing Impairment in DFNA2/KCNQ4 and DFNA9/COCH

Abstract

At similar levels of hearing impairment, DFNA2/KCNQ4-affected patients showed better speech recognition performance than DFNA9/COCH-affected patients.

A Novel Mutation Identified in the <i>DFNA5</i> Gene in a Dutch Family: A Clinical and Genetic Evaluation

“…At a given level of hearing impairment, DFNA5 patients of both families generally showed recognition scores that were better than those of DFNA9 patients but worse than those of DFNA2 patients. As previously described [16], the high-frequency sensorineural hearing impairment of DFNA2 may be attributed to lack of expression of potassium channels, especially in the inner hair cells of the lower turns in the cochlea. Relatively better speech recognition in DFNA2 was explained by relative sparing of outer hair cell function in this region preserving pre-amplification and fine-tuning mechanisms.…”

“…The difference in speech recognition between both families might be explained by the more favourable thresholds in the speech frequencies in the first four decades of life, demonstrated by the ARTA of the present family. Table 1 and figure 6 include data derived from previous reports on DFNA2 and DFNA9 [16]. Straight lines were fitted for X 1 X 90 to approximate the regression curves.…”

“…Cross-sectional binaural mean phoneme recognition scores were plotted for all mutation carriers against age and binaural mean PTA at 1, 2 and 4 kHz (pure-tone average in decibels hearing level). Non-linear regression analysis was used to fit sigmoidal doseresponse curves with variable slope, as previously described [16]. Outlying values were excluded, if necessary.…”

Variable degrees of hearing impairment in a Dutch DFNX4 (DFN6) family

“…DFNA2 (Bom et al, 2001;De Leenheer et al, 2002), DFNA5 (Bischoff et al, 2004), DFNA11 (Bischoff et al, 2006;Tamagawa et al, 2002) and DFNA15 (Frydman et al, 2000;Pauw et al, 2008) have been documented as autosomal dominant hearing impairment disorders with relatively good speech recognition scores. Schraders et al hypothesised that SMPX is important in the development and/or maintenance of sensory hair cells (Schraders et al, 2011).…”

Progressive Sensorineural Hearing Loss and Normal Vestibular Function in a Dutch DFNB7/11 Family with a Novel Mutation in <i>TMC1</i>

“…Maximum monaural phoneme recognition scores were derived from individual performance versus intensity plots. Phoneme recognition scores (averaged over both ears) were plotted against age and the binaural mean pure-tone average at the frequencies of 1, 2 and 4 kHz (PTA 1,2,4 kHz ) [Bom et al, 2001].…”