[Perspectives of molecular genetics of hearing disorders].

In the last few years research efforts have succeeded in detectury the genetic background of several hereditary hearing disorders by molecular biological methods. The genetic code was been decoded for Neurofibromatosis types 1 and 2, as well as for such X-linked diseases as Alport's syndrome or Norrie's disease. Besides the classic genetic tools as chromosomal analysis, molecular biological techniques and methods have become important clinically for the ENT-specialist. In the present review we show the principles and applications of DNA-and RNA-analysis with hybridization techniques in Southern- and Northern-blot techniques, as well as in-situ hybridization and polymerase chain reaction (PCR). These molecular biological techniques will help improve the detection and analysis of hereditary inner ear disorders, but also be able to study in greater detail tumor carcinogenesis and mutagenesis. The various techniques are explained and the applications are demonstrated.