Chapter 10 - Molecular Cytogenetics in Molecular Diagnostics

Abstract

Molecular cytogenetic techniques based on fluorescence in situ hybridization (FISH) applications locating specific, fluorescence-labeled nucleic acid sequences in interphase cells or metaphase chromosomes have become fast, sensitive, and important complementary tools in genetic diagnostics. This chapter summarizes modern molecular cytogenetic diagnostics and gives a brief overview of FISH techniques and multicolor assays used in routine genetic diagnostics. The use of diverse, locus-specific FISH probes and multicolor assays enhances the thorough characterization of numerical and complex chromosome aberrations regardless of their complexity, filling in parts the gap between conventional chromosome banding analysis and molecular genetic studies on the DNA level. Multiple different molecular cytogenetic strategies and applications are used to extend the understanding of diseases and cellular pathology and to generate routine diagnostic tests. Numerous additional experimental-based techniques are established for comparative genomics and other fundamental research questions. In comparison to the first two decades of molecular cytogenetics, the development of new FISH approaches implemented in the routine diagnostic setup has decreased because of new high-resolution microarray-based approaches and high-throughput PCR- or sequencing-based techniques, which have the potential to be automated and are fast and efficient in comparison to cell culture-dependent assays.