A Comparison of Two Molecular Methods for Detecting CALR Mutations in Myeloproliferative Neoplasms

Myeloproliferative neoplasms (MPN) are hematopoietic disorders characterized by abnormal proliferation of the myeloid lineage. Three classic subtypes are polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). These disorders are well known for their association with the JAK2 V617F mutation, in addition to mutations in MPL exon 10, and JAK2 exon 12. CALR mutations were detected in approximately 20% to 25% of patients with ET and PMF and not in patients with PV. Most CALR mutations were deletions and insertions in exon 9, which caused frameshift mutations.

This study included 60 Taiwanese patients with MPN. We identified CALR mutations in patients with MPN using the high-resolution melting (HRM) analysis. Additionally, the HRM analysis was compared with ipsogen CALR RGQ PCR. To confirm the results of HRM and ipsogen CALR RGQ PCR, sequencing analysis was also conducted all the samples.

Up to 6.25% of CALR mutations were successfully detected in patients with MPN using HRM analysis. Eight out of 65 patients (12.3%) were positive for the presence of CALR mutation, including p.L367fs*46 and p.K385fs*47. The results proved 100% comparable to those obtained using ipsogen CALR RGQ PCR.

The HRM analysis and ipsogen CALR RGQ PCR are feasible and reliable techniques for the detection of CALR mutation. Furthermore, HRM offers several benefits, for example, it is time-saving, inexpensive, and does not require many personnel.