[Hereditary ataxia-problems in the classification, genetics and genetic counseling].

Heredoataxias correspond to a larger number of etiologically different and for the greatest part not yet clarified neurogenic clinical pictures, the common characteristics of which are only the heredity and the leading symptoms of the spinocerebellar ataxia. A systematization and classification of the heredoataxias is therefore above all still based on clinical and pathologo-anatomical signs and may scarcely consider etiologic points of view. Own observations of two of the most important hereditary forms of ataxia, of Friedreich's disease and of the autosomal dominant cerebellar ataxias (Pierre Marie) make clear the problems of the diagnostic limitation and of the genetic advice. From these observations and from the literature references for an optimum subtile clinical and paraclinical diagnostics in heredoataxias are derived.