Microarray-based comparative genomic hybridization

Definition

Microarray-based comparative genomic hybridization (aCGH) is a technique used to detect and quantify genomic copy number variations across the genome. This method allows researchers to compare the DNA of a test sample against a reference sample to identify structural variations, such as deletions, duplications, and amplifications, that can be associated with various genetic disorders or diseases.

5 Must Know Facts For Your Next Test

1. aCGH utilizes a microarray platform to simultaneously analyze thousands of genomic regions, providing a high-throughput method for detecting genomic alterations.
2. This technique is particularly useful in clinical settings for diagnosing genetic disorders such as cancer, developmental delays, and congenital anomalies by identifying pathogenic copy number variations.
3. The data obtained from aCGH can be visualized as a ratio of fluorescence intensities between the test and reference samples, revealing regions of gain or loss in the genome.
4. aCGH is less labor-intensive and provides more comprehensive coverage of the genome compared to traditional methods like karyotyping and single-gene testing.
5. Interpretation of aCGH results requires careful analysis, as not all detected copy number variations are clinically significant or associated with disease.

Review Questions

• How does microarray-based comparative genomic hybridization enhance our understanding of genomic abnormalities?
  • Microarray-based comparative genomic hybridization enhances our understanding of genomic abnormalities by allowing for the simultaneous analysis of multiple regions across the genome. This high-throughput approach enables researchers to identify copy number variations that may not be detected through conventional methods. By comparing the DNA of a test sample with a reference sample, it becomes easier to pinpoint structural variations that could be linked to various genetic disorders or diseases.
• Discuss the advantages and limitations of using aCGH in clinical diagnostics for genetic disorders.
  • The advantages of using microarray-based comparative genomic hybridization in clinical diagnostics include its ability to provide a comprehensive overview of genomic alterations quickly and efficiently. It identifies a wide range of structural variations that can be linked to genetic disorders. However, limitations include potential difficulties in interpreting the clinical significance of detected copy number variations, as not all changes are pathogenic. Additionally, false positives or negatives can occur, requiring further validation through complementary techniques.
• Evaluate the role of microarray-based comparative genomic hybridization in advancing personalized medicine and targeted therapies.
  • Microarray-based comparative genomic hybridization plays a significant role in advancing personalized medicine by enabling precise identification of genetic alterations that contribute to disease. This knowledge facilitates the development of targeted therapies tailored to individual patients based on their unique genomic profiles. By understanding specific copy number variations associated with a patient's condition, healthcare providers can make informed decisions regarding treatment options, ultimately leading to improved patient outcomes and more effective management of genetic disorders.

Related terms

Copy Number Variation (CNV): A type of structural variation in the genome that involves the duplication or deletion of sections of DNA, resulting in differences in the number of copies of particular genes.

Fluorescent In Situ Hybridization (FISH): A technique that uses fluorescent probes to detect and localize specific DNA sequences on chromosomes, often used for identifying structural chromosomal abnormalities.

Structural Variants: Large-scale alterations in the genome that include duplications, deletions, inversions, and translocations of DNA segments, which can influence gene function and contribute to genetic diversity.