A Dutch family with progressive sensorineural hearing impairment linked tothe DFNA2 region

We studied a Dutch family with DFNA2-linked progressive sensorineural heari ng impairment (SNHI). Recent audiograms were obtained from 18 of the affect ed persons (age 7-81 years) and were used in a gene-linkage analysis. Linea r regression analysis of the audiograms, using binaural mean thresholds, di sclosed on average a descending slope of approximately 10 dB/octave at any age and an annual threshold increase at any frequency of about 0.7 dB/year. There may have been substantial congenital impairment at higher frequencie s, but longitudinal analysis of hearing impairment in the youngest case, wh o was followed from age 5 years, suggested that the most significant change s in hearing may have occurred in the first two decades of life. Linkage an alysis was carried out with special attention to the DFNA2 region because h earing trends were very similar to families previously linked to DFNA2. Lin kage to DFNA2 was established with maximum lod scores of 4.7 and 3.2 for th e flanking markers of the DFNA2 region (D1S432;MYCL1).