Resolving Breakpoints of Chromosomal Rearrangements at the Nucleotide Level Using Sanger Sequencing

Area of Science:

• Genetics
• Genomics
• Molecular Biology

Background:

• Cytogenetic tools increasingly rely on genome sequencing for detecting chromosomal abnormalities.
• Current sequence-based methods for structural variants lack nucleotide resolution for breakpoint interpretation.
• Accurate breakpoint characterization is crucial for understanding gene disruption in chromosomal abnormalities.

Purpose of the Study:

• To present a protocol for characterizing structural variants at nucleotide resolution.
• To enable precise localization of chromosomal breakpoints for improved diagnostic interpretation.
• To integrate Sanger sequencing with long-molecule genome sequencing methods.

Main Methods:

• Primer design for junction amplification at translocations and inversions.
• Amplification of derivative chromosomes using long-range or hot-start polymerase.
• DNA preparation for Sanger sequencing.
• Interpretation and reporting of breakpoints using Sanger sequencing data.

Main Results:

• The protocol allows for the characterization of structural variants at nucleotide resolution.
• Enables precise identification of breakpoints in chromosomal abnormalities.
• Provides a method to overcome limitations of existing sequence-based techniques.

Conclusions:

• This protocol offers a reliable method for nucleotide-level breakpoint characterization.
• Enhances the diagnostic utility of genome sequencing for chromosomal abnormalities.
• Facilitates accurate interpretation of gene disruption resulting from structural variants.