[Different forms of deafness in Treacher - Collins-Syndrome, shown on a family over three generations (author's transl)].

A Treacher Collins-syndrome has been followed up in a family over 3 generations. We found a change in deafness from grand parents- and parents-generation to the third one. The first two showed an inner ear deafness, the latter the well-known conduction deafness. The phenotype becomes more and more extensive in the following generations. Simultaneous with this development the deafness becomes more typical. In theory the inner ear deafness could either be explained as the final stage of a long standing conductive deafness or it is part of an incomplete developed syndrome.