A follow-up study in a family with dominant progressive inner ear deafness

A family with dominant progressive inner ear deafness beginning in the high tones has been examined in 1962, 1968 and 1978. The audiometric data of 86 affected members (376 audiograms) were studied by 1) determination of averages, 2) principal component and factor analysis, and 3) curve fitting procedures. The hearing appeared to deteriorate in six characteristic phases with a separate deterioration for the high and the low frequencies. The hearing loss was equal for the R and L ear; in females low tone loss was greater than in males; in branch II the hearing loss proceeded more rapidly than in other branches. No abnormal excretion of organic acids in the urine could be established.