The clinical utility of a custom-developed targeted next-generation sequencing assay for detection of mutations associated with Philadelphia-negative chronic myeloproliferative neoplasms: Two case examples with CALR exon 9 mutations

We have developed a highly targeted custom next generation sequencing-based test targeting JAK2 exons 12 and 14, CALR exon 9, and MPL exon 10, which are implicated in Philadelphia-negative chronic myeloproliferative neoplasms. The assay is capable of ultra-high sequencing depth and producing mutational detection sensitivities of 0.5% and below. We have validated the performance of the test through orthogonal testing and demonstrated a high degree of multiplexing with up to 50 samples in a single run. We show the clinical utility of this test through the description of a couple of cases with myeloproliferative disorders with Type-II and Type-II-like mutations in exon 9 of the CALR gene.