The prevalence of CALR mutations in a cohort of patients with myeloproliferative neoplasms

• Published in: International journal of laboratory hematology 2016-02, Vol.38 (1), p.102-106
• Main Authors: Grinsztejn, E., Percy, M. J., McClenaghan, D., Quintana, M., Cuthbert, R. J. G., McMullin, M. F.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; calreticulin; Calreticulin - genetics; Cohort Studies; Female; Humans; Janus Kinase 2 - genetics; Male; Middle Aged; Mutation; mutations; Myeloproliferative; Myeloproliferative Disorders - diagnosis; Myeloproliferative Disorders - genetics; Myeloproliferative Disorders - mortality; Prevalence; Prognosis; Receptors, Thrombopoietin - genetics
• ISSN: 1751-5521; 1751-553X
• DOI: 10.1111/ijlh.12447

Summary Introduction To investigate the prevalence of calreticulin (CALR) mutations in JAK2‐ and MPL‐non‐mutated patients with suspected myeloproliferative neoplasm (MPN) from a large MPN clinic and confirm a diagnosis of MPN. Methods JAK2/MPL‐non‐mutated patients from the Belfast City Hospital (BCH) with either of the MPNs – ET or MF – and diagnosed between 1988 and 2014 were selected for CALR screen. All cases were validated according to the WHO 2008 classification for MPNs. Statistical analysis was performed with Minitab 16 Statistical Software package. Exon 9 of CALR was amplified by PCR using genomic DNA, and mutations were detected by fragment analysis. Results Of the 62 JAK2/MPL‐non‐mutated MPN patients screened, 57 had ET and 5 had MF; 34 patients (53.1%) carried CALR mutations. Three of 5 MF patients were CALR positive. Thirty‐one ET patients (54.3%) harboured CALR mutation, whereas 26 (45.7%) were classified as ‘triple negatives’. Conclusion Detection of CALR mutations in a cohort of JAK2/MPL‐non‐mutated patients with suspected MPN confirmed the diagnosis of MPN in around 53% of cases. This is lower than initially reported, but similar to subsequent studies. However, a sizable cohort of patients remains lacking a specific molecular marker.