The diagnosis of hereditary breast and ovarian cancer is based on the detection of germline alterations in BRCA1 among other genes. However, structural variants can be difficult to assess with standard molecular techniques. In the recent years, Oxford Nanopore long-read sequencing has proved its relevance to accurately and rapidly provide genetic diagnoses of these types of variants. In our study, we resolved a germline tandem duplication of exon 18 to 20 of BRCA1 using Nanopore sequencing with adaptive sampling enrichment, classifying the variant as pathogenic within ten days. This study suggests that Nanopore adaptive sampling is an efficient technique for investigating structural variants suitable for clinical setting. (By Dr Mathilde Filser, https://jmg.bmj.com/content/early/2023/05/31/jmg-2023-109155 )