Authors : Ketki Kelkar, Siddharth Anand, Nikita Somani, Vijay Ramanan, Shatakshi Ranade, Kunal Patil, Trupti Ragte-Wathare, Priyanka Gangodkar, Kavita Khatod, Meenal Agarwal
DOI : 10.18231/j.ijpo.2022.058
Volume : 9
Issue : 3
Year : 2022
Page No : 248-252
Myeloproliferative neoplasms (MPNs) are caused by somatic pathogenic variants that stimulate increased production and clonal expansion of CD34 multipotent hematopoietic stem cells. Recent World Health Organization (WHO) diagnostic criteria for the diagnosis of Philadelphia chromosome (Ph) negative MPNs includes detection of mutations in the Janus Kinase 2 (JAK2), myeloproliferative leukemia (MPL), and calreticulin (JAK2) genes. The purpose of this study was to demonstrate the clinical utility of an in-house next-generation sequencing (NGS) assay targeting only these canonical genes for the molecular diagnosis of patients with Ph-negative MPNs. We tested 274 samples of patients clinically suspected of having Ph-negative MPNs using an in-house developed NGS panel. The assay consists of two parts, a multiplexed PCR and a highly multiplexed NGS workflow capable of handling diverse samples. The assay is capable of simultaneously detecting mutations in JAK2 exons 12 and 14, CALR exon 9, and MPL exon 10.
Of the 274 samples tested, 49 samples harbored mutations in the JAK2 gene (48 for the JAK2 V617F and 1 for JAK2 exon 12), 31 harbored mutations in the CALR gene, and two harbored mutations in the MPL gene. One sample harbored a mutation each in the MPL and CALR genes. Here, we present the distribution of mutations in an Indian cohort of 274 patients from India with Ph-negative MPNs. Moreover, we have successfully demonstrated the clinical utility of our in-house multiplexed NGS assay for the molecular diagnosis of MPNs with varying mutation depths.
Keywords: CALR, JAK2, MPL, Next generation sequencing, Myeloproliferative neoplasm, Philadelphia negative MPN 2.