CGHmikroarrayek

CGH mikroarrayek, also known as array comparative genomic hybridization (array CGH), is a molecular cytogenetic technique used to detect and quantify chromosomal copy number variations (CNVs) across the entire genome. It is an advancement over traditional karyotyping and is widely used in genetic diagnostics and research. The technique compares the amount of DNA obtained from a test sample (e.g., from a patient) with that from a reference sample, which is assumed to have a normal chromosomal complement.

The process involves labeling DNA from both samples with different fluorescent dyes. These labeled DNA samples are then hybridized to a microarray, which contains thousands of DNA probes spotted in a specific order. These probes represent specific genomic regions, often overlapping and covering the entire genome at a high resolution. Regions where the test DNA is amplified (gain) will show a stronger fluorescent signal from its dye compared to the reference DNA, while regions where the test DNA is deleted (loss) will show a weaker signal.

The fluorescence intensity ratio between the test and reference samples for each probe is quantified, allowing for the detection of gains and losses of chromosomal segments. This information is critical for identifying genetic abnormalities associated with various congenital disorders, developmental delays, intellectual disabilities, and certain types of cancer. Array CGH offers higher resolution and sensitivity compared to traditional methods, enabling the detection of smaller CNVs that might be missed otherwise. It has become a first-tier diagnostic test for individuals with unexplained developmental and epileptic encephalopathies.