In Search of Disease Genes Array CGH as a Molecular Cytogenetic Diagnostic Tool

摘要

In searching for chromosomal aberrations, karyotyping of banded chromosomes by microscopic analysis of metaphase spreads is one of the most widely used techniques in clinical cytogenetics (Trask, 2002). All kinds of numerical, as well as structural aberrations like translocations, inversions, deletions, duplications and amplifications, can be detected by this method. The quality of individual karyotypes is measured by band level estimations, where three band levels are widely used; 400-, 550- and 850-bands. With a total genome size of -3000 Mb, the average resolution for detecting chromosomal rearrangements by karyotyping varies between 3.5 Mb and 7.5 Mb, also depending on the genomic location (band) of the alteration.