ADVANCED CYTOGENETIC ENGINEERING TECHNIQUES FOR DETECTING RARE CHROMOSOMAL REARRANGEMENTS

Abstract

Background: Rare rearrangement of are associated alongside birth defects, infertility, haematological malignancies and various cancers. Standard cytogenetics may not detect cryptic or low level structural aberrations because of its limited resolution as well as sensitivity.

Objective: This study aimed for assessing advanced cytogenetic engineering methods for accurate detection as well as characterization of rare chromosomal reorganization.

Methodology: Peripheral blood, bone marrow and tumor biopsy samples were analyzed by combined cytogenetic approaches, including G-banded karyotyping, fluorescent in situ hybridization (FISH), spectral karyotyping (SKY), array compared genomic hybridization (array-CGH), next generation sequencing (NGS) and CRISPR-based chromosomal imaging. Structural variant analysis and the breakpoint mapping were performed using bioinformatics tools.

Results: The multi-platform approach resulted in 99% diagnostic sensitivity compared to 96% sensitivity for NGS alone for detection of cryptic translocations, microdeletions, inversions and mosaic rearrangements. Array-CGH identified 24 cases of microdeletion and FISH and SKY have well characterized complicated chromosomal abnormalities.

Conclusion: The use of elaborate methods of cytogenetic engineering considerably improves the accuracy of identifying a rare rearrangements of the Molecular and sequencing based approaches complement each other to provide increased genomic resolution, and have great potential for precision assessment and personalized medicine .