Cytogenetics Quiz

Cytogenetics

Karyotyping

• Definition: Karyotyping is the process of creating an image of an individual's chromosomes to identify any abnormalities.
• Methods:
  • Conventional cytogenetics: uses trypsin-Giemsa banding to stain and visualize chromosomes.
  • Molecular karyotyping: uses fluorescence in situ hybridization (FISH) or array comparative genomic hybridization (aCGH) to identify genetic changes.
• Applications:
  • Prenatal diagnosis of chromosomal abnormalities.
  • Diagnosis of genetic disorders, such as Down syndrome.
  • Cancer diagnosis and prognosis.

Chromosome Abnormalities

• Types of abnormalities:
  • Numerical abnormalities: changes in the number of chromosomes (e.g., trisomy, monosomy).
  • Structural abnormalities: changes in the structure of chromosomes (e.g., deletions, duplications, translocations).
• Causes of abnormalities:
  • Meiotic errors: errors during meiosis can lead to abnormalities.
  • Mitotic errors: errors during mitosis can lead to abnormalities in somatic cells.
• Consequences of abnormalities:
  • Developmental disorders: abnormalities can lead to developmental disorders, such as Down syndrome.
  • Cancer: abnormalities can contribute to the development and progression of cancer.

Molecular Cytogenetics

• Definition: Molecular cytogenetics combines molecular biology and cytogenetics to study the structure and function of chromosomes.
• Techniques:
  • Fluorescence in situ hybridization (FISH): uses fluorescent probes to detect specific DNA sequences.
  • Array comparative genomic hybridization (aCGH): compares the genomic DNA of two samples to identify copy number changes.
• Applications:
  • Cancer diagnosis: identifies genetic changes associated with cancer.
  • Prenatal diagnosis: identifies chromosomal abnormalities in prenatal samples.
  • Genetic disorder diagnosis: identifies genetic changes associated with genetic disorders.