[Neurogenetics--the challenge for neurology. 1. Neurogenetic diseases].

Progress in molecular genetics has provided insight into a number of neurogenetic disorders. The chromosomal location of the genes for Huntington's disease, Wilson's disease, myotonic dystrophy and Friedreich's ataxia are now known. In families affected by these illnesses, linkage analysis can now be employed for presymptomatic or prenatal diagnosis. The genes for Duchenne and Becker muscular dystrophy and neurofibromatosis I have been cloned and sequenced, allowing the direct analysis of the genetic defect in many cases, and thereby providing further insight into the pathophysiology. In addition, the classification of several neurogenetic diseases, such as the hereditary motor and sensory neuropathies or the spinal muscular atrophies can now be based on the chromosomal location of the affected gene(s).