[Diagnostic studies in patients and relatives with hereditary neuromuscular diseases].

Preclinical and prenatal diagnosis as well as detection of healthy carriers is now theoretically possible for more than 200 monogenic inherited neurological and neuromuscular diseases and practically performed in many of them. However, it has to be made a condition, that the diagnosis in the index patient is secured by all clinical and laboratory methods available today, and that the specific mutation has been localized or even sequenced, and of course the families must give their full consent to the examinations. It is important to submit material for the different laboratory investigations from patients and their relatives as early as possible [biopsies, blood samples for DNA, etc.], at least for rapidly progressive diseases with a poor prognosis. In order to obtain very high probabilities in diagnostic predictions a family has to be examined either with mutation-specific DNA-probes and/or with probes for closely linked polymorphic DNA-markers. This requires a close cooperation between genetic services and DNA-laboratories on the one hand and the family doctors, specialists and clinics on the other. Specific strategies are discussed for hereditary sensory and motor neuropathy [HMSN la or Charcot-Marie-Tooth disease], Duchenne und Becker muscular dystrophy and childhood spinal muscular atrophies.