What is CGH blood test?

What is CGH blood test?

Comparative genomic hybridization (CGH) is a molecular cytogenetic method for analysing copy number variations (CNVs) relative to ploidy level in the DNA of a test sample compared to a reference sample, without the need for culturing cells.

What is CGH disease?

Comparative genomic hybridization (CGH), also referred to as chromosomal microarray analysis (CMA), and array CGH (aCGH), is a method of genetic testing that may identify small deletions and duplications of the subtelomers, each pericentromeric region and other chromosome regions.

What can CGH detect?

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 CGH technique?

Comparative genomic hybridisation (CGH) is a technique that permits the detection of chromosomal copy number changes without the need for cell culturing. It provides a global overview of chromosomal gains and losses throughout the whole genome of a tumour.

What is CGH array for?

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.

Can CGH detect trisomy?

It tests for the most common chromosome abnormalities: Down syndrome (trisomy 21), Edwards syndrome (trisomy 18) and Patau syndrome (trisomy 13). If the QF-PCR result is normal the laboratory will go on to perform the array CGH test.

What is microarray CGH?

Microarray CGH utilises tens of thousands of DNA probes to simultaneously detect and accurately characterise copy number imbalance (deletions and duplications) from across the whole genome.

What is the difference between CGH and microarray?

In the clinical context, DNA microarrays are used to detect imbalances in chromosomal regions. CGH‐based arrays (aCGH) measure the quantity of genomic DNA in a patient’s sample and compares it with the genomic DNA in a nor- mal control sample.

Can CGH detect polyploidy?

However, some changes can be made to circumvent these limitations, for example, the incorporation of single nucleotide polymorphisms probes into aCGH allows the detection of polyploidy.

What is aCGH microarray test?

Array CGH (also known as microarray, or chromosome microarray (CMA)) is an ultra-high resolution way of objectively and quantitatively detecting whether a patient’s DNA has losses (deletions) or gains (duplications, triplications etc) which are pathogenic and therefore explain their clinical problems.

Is CGH same as microarray?

These very small changes are often called microdeletions and microduplications. Array CGH is also sometimes called CGH array, aCGH or simply a microarray.

What are the limitations of CGH test?

Limitations of CGH and array CGH. A main disadvantage of conventional CGH is its inability to detect structural chromosomal aberrations without copy number changes, such as mosaicism, balanced chromosomal translocations, and inversions. CGH can also only detect gains and losses relative to the ploidy level.

What does CGH stand for?

aCGH: array-based CGH ALL: acute lymphoblastic leukemia BAC: bacterial artificial chromosome BASE: BioArray Software Environment CGH: comparative genomic hybridization CNA: copy number aberration CNV: copy number variation FISH: Fluorescence in situ hybridization IQR: Inter Quartile Range

What is the purpose of using conventional CGH?

Conventional CGH has been used mainly for the identification of chromosomal regions that are recurrently lost or gained in tumors, as well as for the diagnosis and prognosis of cancer. This approach can also be used to study chromosomal aberrations in fetal and neonatal genomes.

What is the difference between CGH and array CGH?

With the introduction of array CGH, the main limitation of conventional CGH, a low resolution, is overcome. In array CGH, the metaphase chromosomes are replaced by cloned DNA fragments (+100–200 kb) of which the exact chromosomal location is known.