Comparison of the Diagnostic Accuracy of Next Generation Sequencing and Microarray Resequencing Methods for Detection of BRCA1 and BRCA2 Gene Mutations

Objective: Breast cancer constitutes 29 % of estimated new cases of cancer in women, and it is also one of the major cause of death in all cancer types. In this study, DNA samples of familial breast cancer patients with BRCA1 and BRCA2 mutations which had been analyzed using conventional DNA sequencing method, were also analyzed with new methods including microarray and next generation sequencing (NGS) in order to compare their results Methods: Seven patients with BRCA1 mutation, one patient with BRCA2 mutation, and two controls were included. All samples for the microarray method were studied on the GeneChip 3000 Scanner (Affymetrix) system and then analyzed on the Affymetrix GeneChip Resequencing Analysis Software (GSEQ® v4.0) system. Four patients from the patient group were selected for next generation sequencing and were analyzed on GS Junior 454 (Roche, Prague, Czech Republic) system. The raw data had been analysed by SeqPilot SeqNext module (v4.0, JSI medical systems, Kippenheim, Germany). Results: Microarray resequencing analysis did not detect the mutations defined by conventional sequencing in patients, but mutations were detected in all of the 4 patients in the next generation sequencing. Conclusion: Our study detected the NGS to be reliable as conventional DNA sequencing for studying BRCA1/BRCA2 gene mutations. However, we suggest to confirm the NGS results with a conventional method because of homopolymer sequences which may cause false positive results.