Molecular cytogenetics

Molecular Cytogenetics

DAPI stained karyotype of Aprasia parapulchella female.

Molecular cytogenetics is a branch of cytogenetics that combines the techniques of molecular biology and cytogenetics to study the structure and function of chromosomes. This field has revolutionized the ability to detect chromosomal abnormalities and has applications in genetic research, cancer diagnosis, and prenatal diagnosis.

Techniques

Molecular cytogenetics employs several advanced techniques to analyze chromosomes at a molecular level. Some of the key techniques include:

Fluorescence In Situ Hybridization (FISH)

Fluorescence in situ hybridization (FISH) is a technique used to detect and localize the presence or absence of specific DNA sequences on chromosomes. It uses fluorescent probes that bind to only those parts of the chromosome with which they show a high degree of sequence complementarity.

Comparative Genomic Hybridization (CGH)

Comparative genomic hybridization (CGH) is a molecular cytogenetic method for analyzing copy number variations (CNVs) in the DNA content of a cell. It allows for the detection of genomic imbalances such as deletions and duplications across the entire genome.

Spectral Karyotyping (SKY)

Spectral karyotyping (SKY) is a technique that uses multiple fluorescent dyes to paint each chromosome in a different color. This allows for the visualization of chromosomal rearrangements and abnormalities.

Applications

Molecular cytogenetics has a wide range of applications in various fields of medicine and biology.

Cancer Diagnosis

BCR-ABL fusion gene detected in chronic myeloid leukemia.

In oncology, molecular cytogenetics is used to identify chromosomal abnormalities associated with different types of cancer. For example, the Philadelphia chromosome, a result of a translocation between chromosomes 9 and 22, is detected using FISH in patients with chronic myeloid leukemia.

Prenatal Diagnosis

Molecular cytogenetics is also used in prenatal diagnosis to detect chromosomal abnormalities such as Down syndrome, Edwards syndrome, and Patau syndrome. Techniques like FISH can be applied to amniotic fluid or chorionic villus sampling to provide early diagnosis.

Genetic Research

In genetic research, molecular cytogenetics is used to study the genome organization and to map genes to specific locations on chromosomes. This helps in understanding the genetic basis of diseases and in identifying potential targets for gene therapy.

Future Directions

The field of molecular cytogenetics continues to evolve with advancements in technology. The development of next-generation sequencing (NGS) and CRISPR-Cas9 gene editing are expected to further enhance the capabilities of molecular cytogenetics in diagnosing and treating genetic disorders.

Related Pages

• Cytogenetics
• Genetic testing
• Chromosome abnormality
• Genomics