[Neuromuscular diseases (NME). I. Spinal muscular atrophy, peripheral nerve diseases, congenital myasthenia gravis].

Among the group of clinically and genetically heterogeneous spinal muscular atrophies(SMA), the autosomal recessive proximal types I-III are the most frequent. They are caused by mutations of the telomeric copy of the survival motor neuron gene (SMN1) on chromosome sq while loss of the centromeric copy (SMN2) does not lead to SMA. The conservation of exon 7 in the SMN2 copy seems to be crucial for possible causal therapy options. The genetic defect is also known for spinal muscular atrophy with respiratory distress. Hereditary polyneuropathies are caused by mutations in several genes on different chromosomes. Genetic and phenotypic heterogeneity must be considered. Data on clinical symptoms, inheritance, and neurophysiology are obligatory for the most effective molecular analysis. Hereditary congenital myasthenic syndromes are clinically, genetically, and pathogenetically heterogeneous. The diagnostic significance of molecular genetic analyses is still increasing. Therapeutic options include oral medication and assisted ventilation as needed.