Chromosomal Array CGH - Cancer Profile - Prenatal, Amniotic Fluid

Chromosomal Array, Comparative genomic hybridization (CGH) is a confirmatory & an invasive test which is done prenatally to identify foetal anomalies i.e., chromosomal aneuploidy, other large structural changes, sub microscopic abnormalities that are not detected by karyotyping. CGH Chromosome Array Test requires detailed clinical history including anomaly scan report and a duly filled consent form (Form G)

Array CGH Prenatal helps in the detection of copy number variations (CNV) changes (microdeletions and microduplications).

Conventional karyotyping is used to detect chromosomal problems in about 35% of pregnancies. However, its accuracy depends on the quantity and type of fetal ultrasonography anomalies present. Prenatal karyotyping is a reliable procedure that can identify the majority of germline chromosomal abnormalities. Most of these anomalies are associated with the phenotype. For postnatal diagnosis of people with congenital defects and intellectual incapacity, array-comparative genomic hybridization (CGH)/(single nucleotide polymorphism is very common. It has a high probability of accurate abnormality detection and is automation-friendly. This makes it the perfect choice for a prenatal diagnosis.

To discover fetal defects such as chromosomal aneuploidy, other significant structural changes, and submicroscopic abnormalities that are not picked up by karyotyping, a confirming and invasive test called CGH is performed during pregnancy. A complete consent form and a clinical history that includes the anomaly scan report are required for the test (Form G).

CGH has been established to aid in prenatal diagnosis. It is used to examine structural chromosomal rearrangements linked to copy number variations on a genome-wide scale. Test and standard genomic DNAs are fluorescently labeled with two separate fluorochromes and hybridized to healthy metaphase chromosomes in CGH. Genome-wide copy number alterations, such as homo- or heterozygous deletions, gains, or amplifications, can be detected by determining the relative genomic copy number throughout each chromosome.

Written by: Dr Vishal Wadhwa M.D, D.N.B Microbiology, Medical Affairs