Molecular genetics: applications to the clinical neurosciences.

Application of molecular biology, by means of linkage analysis and DNA probes that demonstrate restriction fragment length polymorphisms (RFLPs), has resulted in the chromosomal localization of the genes responsible for a number of neurological disorders. Characterization of the structure and function of individual genes for these diseases is in an early stage, but information available indicates that the molecular mechanisms underlying phenotypic expression of neurological diseases encompass a wide range of genetic errors ranging from the most minor (a single-base pair mutation) to large chromosomal deletions. Linkage analysis can now be used for genetic counseling in several of these disorders.