What is detected by an array CGH analysis?
Array CGH detects microscopic and submicroscopic deletions and duplications at targeted areas of the genome, including loci of known microdeletion/microduplication syndromes, subtelomeric regions, and pericentromeric regions. Array CGH will also identify marker chromosomes, some cases of mosaicism, and aneuploidy.
What is a chromosomal imbalance?
Genetic imbalance is to describe situation when the genome of a cell or organism has more copies of some genes than other genes due to chromosomal rearrangements or aneuploidy. Changes in gene dosage, the number of times a given gene is present in the cell nucleus, can create a genetic imbalance.
When do you use CGH vs fish?
Summary – FISH vs CGH FISH facilitates the detection of specific DNA sequence on a chromosome using fluorescently labeled probes while CGH facilitates the detection of alterations in the genomic DNA.
Can CGH detect aneuploidy?
By using markers that cover most of the genome, not only aneuploidy can be detected in single cells but also translocations. Our validation results indicate that array CGH has a 6Mb resolution in single cells, and thus the majority of translocations can be analyzed since this is also the limit of karyotyping.
When is array CGH used?
Array CGH applications are mainly directed at detecting genomic abnormalities in cancer. However, array CGH is also suitable for the analysis of DNA copy number aberrations that cause human genetic disorders. That is, array CGH is employed to uncover deletions, amplifications, breakpoints and ploidy abnormalities.
Why would extra chromosomes result to abnormal phenotypes?
By definition, aneuploid cells have an abnormal number of chromosomes. Because each chromosome contains hundreds of genes, the addition or loss of even a single chromosome disrupts the existing equilibrium in cells, and in most cases, is not compatible with life.
What is array CGH resolution?
Array CGH is characterized by a high resolution, its major advantage with respect to conventional CGH. The standard resolution varies between 1 and 5 Mb, but can be increased up to approximately 40 kb by supplementing the array with extra clones.
Can CGH detect translocation?
Array comparative genomic hybridization (array-CGH), which facilitates to detect unbalanced reciprocal translocation and allows screening aneuploidy for chromosomes, has been repeatedly verified to be valid for diagnosis of translocations in preimplantation human embryos.
What is Array CGH genetic testing?
Array CGH is a technique which screens the whole genome to detect copy number changes (unbalanced gains/duplications and losses/deletions of genetic material) which may be contributing to a child’s phenotype.