WHAT IS A CGH?

Have you ever heard of a CGH, or Comparative Genomic Hybridization? If not, you're not alone. This relatively new technology is still in its early stages of development, but it has the potential to revolutionize the way we diagnose and treat genetic diseases.

Background on CGH

CGH is a molecular cytogenetic technique which seeks to detect and map DNA sequence copy number variations (CNVs) across the entire genome. It was developed in the early 1990s as a way to detect chromosomal abnormalities that are too small to be seen using traditional cytogenetic methods, such as karyotyping.

How CGH Works

To perform CGH, DNA from a patient is labeled with different fluorescent dyes and then mixed with labeled DNA from a healthy control. The two DNA samples are then hybridized to a microarray, which is a glass slide that contains complementary DNA probes for every gene in the genome. The labeled DNA will bind to the probes on the microarray, and the amount of binding will be proportional to the amount of DNA present in the sample.

Applications of CGH

CGH is used to analyze chromosomal aberrations which are often associated with genetic diseases, cancers and congenital disorders.

• Cancer: CGH is used to find chromosomal abnormalities that are commonly associated with cancer, such as deletions, duplications, and translocations. This information can be used to help diagnose cancer, determine the stage of cancer, and predict the likely response to treatment.
• Genetic Diseases: CGH can also be used to diagnose genetic diseases that are caused by chromosomal abnormalities, such as Down syndrome and Fragile X syndrome. CGH can also be used to identify carriers of genetic diseases, who are people who have one copy of a mutated gene but do not have the disease themselves.
• Congenital Disorders: CGH can be used to diagnose congenital disorders that are caused by chromosomal abnormalities, such as heart defects, kidney problems, and cleft lip and palate.

Advantages of CGH

CGH has several advantages over traditional cytogenetic methods.

• Sensitivity: CGH is more sensitive than traditional cytogenetic methods, meaning that it can detect smaller chromosomal abnormalities.
• Specificity: CGH is also more specific than traditional cytogenetic methods, meaning that it is less likely to produce false-positive or false-negative results.
• High-Throughput: CGH can be used to analyze large numbers of samples quickly and easily.
• Cost-Effective: CGH is a relatively cost-effective method for detecting chromosomal abnormalities.

Conclusion

CGH is a powerful new technology that has the potential to revolutionize the way we diagnose and treat genetic diseases. As CGH continues to develop, it is likely to become an even more valuable tool for clinicians and researchers.

Frequently Asked Questions

1. What is the difference between CGH and karyotyping?

Karyotyping is a traditional cytogenetic method that involves staining chromosomes and then examining them under a microscope. CGH is a molecular cytogenetic method that involves labeling DNA with fluorescent dyes and then hybridizing it to a microarray. CGH is more sensitive and specific than karyotyping.

2. What are some of the limitations of CGH?

CGH can only detect chromosomal abnormalities that are large enough to be seen on a microarray. CGH cannot detect single-gene mutations.

3. How is CGH used in clinical practice?

CGH is used to diagnose genetic diseases, cancers, and congenital disorders. CGH can also be used to identify carriers of genetic diseases.

4. What are some of the future applications of CGH?

CGH is likely to be used to develop new treatments for genetic diseases. CGH may also be used to identify individuals who are at risk for developing cancer.

5. Where can I learn more about CGH?

There are many resources available online about CGH. You can also talk to your doctor or a genetic counselor to learn more about CGH.