BreastNext analyzes 17 genes (listed above). All genes are evaluated by next generation sequencing (NGS) or Sanger sequencing of all coding domains, and well into the flanking 5’ and 3’ ends of all the introns and untranslated regions. In addition, sequencing of the promoter region is performed for PTEN (c.-1300 to c.-745). The BRCA2 Portuguese founder mutation, c.156_157insAlu (also known as 384insAlu) is detected by NGS and confirmed by PCR and agarose gel electrophoresis. Clinically significant intronic findings beyond 5 base pairs are always reported. Intronic variants of unknown or unlikely clinical significance are not reported beyond 5 base pairs from the splice junction. Additional Sanger sequencing is performed for any regions missing or with insufficient read depth coverage for reliable heterozygous variant detection. Potentially homozygous variants, variants in regions complicated by pseudogene interference, and variant calls not satisfying depth of coverage and variant allele frequency quality thresholds are verified by Sanger sequencing. Gross deletion/duplication analysis for the covered exons and untranslated regions of all 17 genes is performed using read-depth from NGS data with confirmatory multiplex ligation-dependent probe amplification (MLPA) and/or targeted chromosomal microarray.