NONSYNDROMIC AUTOSOMAL-DOMINANT PROGRESSIVE SENSORINEURAL HEARING-LOSS - AUDIOLOGICAL ANALYSIS OF A PEDIGREE LINKED TO DFNA2

An analysis was performed of the regression of the individual hearing threshold on age in the affected persons in a six-generation Dutch fam ily with nonsyndromic autosomal dominant sensorineural hearing loss, w hich showed linkage to the DFNA2(1p34) region, similar to at least fou r previously reported nonrelated families. The offset threshold was si gnificantly higher adi the high frequencies (around 30 dB at 2 to 8 kH z) than at the lower ones (approximately 0 dB at 0.25 to 1 kHz). Heari ng impairment at the higher frequencies may therefore have been? prese nt already at birth or ina early childhood. The regression coefficient , or the 'annual threshold increase,' expressed in dB/y, was about 1 d B/y on average, hut the higher frequencies (1 to 8 kHz) showed signifi cantly more rapid progression than the lower frequencies (0.25 to 0.5 kHz).