Application of fluorescence in situ hybridization (FISH) in clinical genetics

In this paper we present the results of cytogenetic and FISH analysis in 20 patient referred for suspected constitutional chromosomal aberrations. The aim of this report is to evaluate the advantages and limitations of routine karyotyping and the FISH method in the detection of various types of genome rearrangements. This study demonstrates a number of advantages of the FISH method over conventional cytogenetic such as the possibility of investigating genomic imbalance in non-dividing cells, the detection of cytogenetically invisible microdeletions and distinction of intra– from interchromosomal rearrangements. The FISH method, however, presents some limitations such as the impossibility of simultaneous detection and identification of every chromosome in a metaphase spread and precise identification of the chromosomal segment involved in duplications, inversions or detetions.