Somatic mutation detection efficiency in EGFR: a comparison between high resolution melting analysis and Sanger...

Area of Science:

• Molecular Biology
• Oncology
• Genetics

Background:

• High-resolution melt (HRM) analysis is a rapid, cost-effective screening tool for somatic gene mutations.
• Previous studies explored HRM performance, but analytical parameters like limit of detection (LOD) and DNA concentration were not fully addressed.
• This study compares HRM and Sanger sequencing for detecting EGFR somatic mutations in non-small cell lung cancer (NSCLC).

Purpose of the Study:

• To compare the mutation detection efficiency of HRM and Sanger sequencing for EGFR somatic mutations.
• To determine the limit of detection for mutant allele fraction and total DNA concentration using both methods.
• To evaluate HRM's analytical performance against Sanger sequencing in NSCLC tumor tissues.

Main Methods:

• Sanger sequencing and HRM were used to determine the limit of detection of minor allele fraction against total DNA concentration.
• Multiplex allele-specific real-time PCR validated mutant and wildtype allele fractions.
• EGFR exons 19 and 21 mutation detection efficiency was compared in 116 FFPE tumor tissues, following screening of 275 tissues by Sanger sequencing.

Main Results:

• HRM detected lower minor allele fractions (0.25%) than Sanger sequencing (1%) for exon 19 EGFR mutations.
• Both methods detected 0.25% minor allele fraction for exon 21 mutations.
• HRM identified additional mutations not detected by Sanger sequencing (28% in exon 19, 40% in exon 21), with 100% sensitivity and 67% specificity.

Conclusions:

• HRM serves as a valuable initial screening test for EGFR somatic mutations in NSCLC.
• Sanger sequencing is essential for confirming HRM-detected mutations.
• Optimizing PCR annealing temperature could enhance Sanger sequencing's limit of detection.