Oncology and Fibroids
Cytogenetics is difficult in solid tumors that too especially in carcinoma cervix due to: (AIIMS Nov. 2011)
|A||High mitotic activity|
|B||Good quality metaphase|
|C||Specimen often not adequate|
|D||Contamination by infection causing organism|
Often contaminated and infested with infective micro organisms
1. Cytogenetics is a branch of genetics that is concerned with the study of the structure and function of the cell, especially the chromosomes.It includes routine analysis of G-Banded chromosomes, other cytogenetic banding techniques, as well as molecular cytogenetics such as fluorescent in situ hybridization (FISH) and comparative genomic hybridization (CGH).
2. Karyotype analysis based on G- or R-banding techniques have been widely applied to the characterization of cytogenetic abnormalities in tumor cells and have contributed significantly to the identification of recurrently involved chromosomal loci and hence to the molecular cloning of cancer causing genes.
3. In many instances, however, the cytogenetic analysis of chromosomes from solid tumors has proven to be challenging.
4. This is due to the often-low mitotic index, the poor quality of metaphase chromosomes, and the sheer number of cytogenetic abnormalities
5. Bacterial contamination is common technical problems in isolation & Extraction of DNA from clinical samples.
6. Cytogenetics in solid tumours is done by FISH technique most commonly which does not require dividing cells or metaphase nuclei. Sample adequacy in tissue biopsy is never an issue