View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector International Journal of Gerontology 8 (2014) 105 Contents lists available at ScienceDirect International Journal of Gerontology journal homepage: www.ijge-online.com Letter to the Editor CALR Mutations in Myeloproliferative Neoplasms* * To the Editor, Ken-Hong Lim Division of Hematology and Oncology, Department of Internal Medicine, The discovery of the JAK2V617F mutation has provided impor- Mackay Memorial Hospital, Taiwan tant insight into the pathogenesis of BCR-ABL1-negative myelopro- Laboratory of Good Clinical Research Center, Department of Medical Research, liferative neoplasms (MPNs) and has revolutionized the diagnosis Mackay Memorial Hospital, Tamsui District, Taiwan and treatment of MPNs. Following JAK2V617F mutation, somatic mutations such as JAK2 exon 12, MPL, LNK, TET2, DNMT3A, IDH1/2, Graduate Institute of Oncology, National Taiwan University College of Medicine, ASXL1, EZH2, SRSF2, and SF3B1 have been identified in MPNs. We Taipei, Taiwan have recently reported the frequency of JAK2V617F and DNMT3A Mackay Medical College, New Taipei City, Taiwan mutations in adult Taiwanese patients with BCR-ABL1-negative Huan-Chau Lin MPNs, and the results are comparable with those in Western coun- Division of Hematology and Oncology, Department of Internal Medicine, 1,2 tries . However, JAK2V617F, MPL, and DNMT3A mutations were not Mackay Memorial Hospital, Taiwan detected in approximately 40% of patients with essential thrombo- cythemia (ET) in our cohort and others’ cohorts. With the help of Laboratory of Good Clinical Research Center, Department of Medical Research, the next-generation sequencing technique, two study groups Mackay Memorial Hospital, Tamsui District, Taiwan have recently demonstrated a high frequency of calreticulin Caleb Gon-Shen Chen (CALR) exon 9 mutations in patients with JAK2V617F-negative ET Division of Hematology and Oncology, Department of Internal Medicine, fi 3,4 and primary myelo brosis . What is important is that both studies Mackay Memorial Hospital, Taiwan showed that CALR exon 9 mutations are mutually exclusive with JAK2V617F and MPL mutations, and are not found in patients with Laboratory of Good Clinical Research Center, Department of Medical Research, polycythemia vera. In screening tests, CALR mutations are also pre- Mackay Memorial Hospital, Tamsui District, Taiwan sent in a few other myeloid neoplasms such as myelodysplastic Institute of Molecular Medicine, National Tsing-Hua University, Hsin-Chu, syndrome, but are absent in solid cancers. The discovery of CALR Taiwan mutations in patients with JAK2 and MPL unmutated ET and pri- mary myelofibrosis has largely filled the gap. We therefore propose Yi-Hao Chiang that CALR mutations should be screened for during the work up of Division of Hematology and Oncology, Department of Internal Medicine, MPNs, especially in patients without the JAK2V617F mutation. Mackay Memorial Hospital, Taiwan 2þ Calreticulin is a calcium (Ca )-binding chaperone in the endo- Laboratory of Good Clinical Research Center, Department of Medical Research, plasmic reticulum. It has an essential role in ensuring proper protein Mackay Memorial Hospital, Tamsui District, Taiwan and glycoprotein folding. The unexpected discovery of CALR muta- tions in MPNs has provided an important clue to the novel biological Chung-Der Hsiao role of CALR in hematopoiesis. It has also opened a new avenue for Department of Bioscience Technology, Chung Yuan Christian University, basic, clinical, and translational research in the field of MPNs. Chung-Li, Taiwan Yuan-Yeh Kuo References Graduate Institute of Oncology, National Taiwan University College of Medicine, Taipei, Taiwan 1. Lin H-C, Chen CG-S, Chang M-C, et al. JAK2 V617F mutation in adult Taiwanese patients with essential thrombocythemia: more prevalent in old patients and * correlated with higher hemoglobin level and higher leukocyte count. Int J Geron- Correspondence to: Dr Ken-Hong Lim, MD, Division of Hematology and tol. 2013;7:40e44. Oncology, Department of Internal Medicine, Mackay Memorial Hospital, 2. Lin H-C, Wang S-C, Chen CG-S, et al. Mutation and lineage analysis of DNMT3A in Number 92, Section 2, Chungshan North Road, Taipei 10449, Taiwan. BCR-ABL1-negative chronic myeloproliferative neoplasms. Int J Gerontol. 2013;7: 186e188. E-mail address: [email protected] (K.-H. Lim). 3. Klampfl T, Gisslinger H, Harutyunyan AS, et al. Somatic mutations of calreticulin in myeloproliferative neoplasms. N Engl J Med. 2013;369:2379e2390. 5 September 2013 4. Nangalia J, Massie CE, Baxter EJ, et al. Somatic CALR mutations in myeloprolifer- Available online 3 June 2014 ative neoplasms with nonmutated JAK2. N Engl J Med. 2013;369:2391e2405. * Conflicts of interest: All authors have no financial interests to declare related to the material in the manuscript. http://dx.doi.org/10.1016/j.ijge.2014.03.001 1873-9598/Copyright © 2014, Taiwan Society of Geriatric Emergency & Critical Care Medicine. Published by Elsevier Taiwan LLC. All rights reserved..