[Diagnostic methodology of genome alteration]

Advances in molecular biology have produced great results concerning with the knowledge about hereditary mechanisms and gene diseases. In the last twenty years the development of discoveries have exceeded the information of clinical pediatricians, and the technology of genetic engineering, evolved from the properties of the DNA molecule, give us powerful diagnostic tools much more specific than those of classical cytogenetics limited to gross disorders of cariotype. Cellular cultures, autoradiography and electrophoresis have been very useful to develop molecular genetics. Using hybridomas a gene can be located into one chromosome. After wards the restriction map may be represented and employed as routine diagnostic procedure. Final objective is the genetic map with the complete sequence of normal and abnormal genes. To do so, more sophisticated methods are coming that still belong to the field of research.