Copy number variants (CNVs) of breast and/or ovarian cancer susceptibility genes are a known class of clinically significant variants.[1],[2] Recent advances in next-generation sequencing (NGS) methods and bioinformatics lead to cost-effective and unified workflow to detect CNV and short sequence variants simultaneously for a panel of genes.[3],[4] However, CNV detection resolution by routine gene panel NGS is often limited to individual exon level without exact CNV breakpoint and direction. Molecular-barcode NGS testing of the proband blood DNA for six genes ( I BRCA1 i , I BRCA2 i , I TP53 i , I PTEN i , I PALB2 i , and I CDH1 i ) detected a CNV of I PALB2 i exon 13 (the last coding exon of I PALB2 i , reference sequence NM 024675.3) at a copy number ratio of 1.57, which was interpreted as a germline heterozygous duplication. We applied the same reverse transcriptase PCR assay from Yang et al[7] on our proband blood RNA and showed that there is no abnormal splicing of I PALB2 i exon 13. [Extracted from the article]