[Current methods of molecular cytogenetics in pre- and postnatal diagnosis of chromosome aberrations]

Progress in prevention of chromosome aberrations is due to utilization of molecular cytogenetic diagnostic methods. The purpose of this trend of clinical cytogenetics is development and utilization of new highly effective methods for analysis of chromosome aberrations. Molecular cytogenetic methods (fluorescent in situ hybridization-FISH) are used for pre- and postnatal identification of chromosome aberrations in mentally retarded children and congenital diseases. These studies are carried out after classical cytogenetic analysis, if it proves to be of no avail. FISH diagnosis pre- and postnatally detects autosomal trisomy, gonosome aneuploidy (including mosaic forms), marker chromosomes, structural chromosome aberrations, including fragile X chromosome syndrome. Rapid (15-30 min) FISH with an original collection of centromere, telomere, and site-specific DNA probes (plasmid, cosmid, PAC and YAC clones) is recommended for molecular cytogenetic diagnosis. FISH diagnosis is an effective complex of methods for pre- and postnatal identification of chromosome aberrations and a necessary supplement to classical cytogenetic diagnosis. Molecular studies of chromosome aberrations are significant for theoretical and applied studies, for they help detect patients with specific chromosome syndromes from a vast group of children with undifferentiated mental retardation and congenital diseases.