A 60-year-old woman presented with 2 years of progressive transfusion-dependent anemia. CBC was as follows: Hb 10.4 g/dL (ref 12-15.5), MCV 94.8 fL (ref 81.6-98.3), RDW 17.7% (ref 11.9-15.5), WBC 4.4x109/L (ref 3.5-10.5), Plt 135x109/L (ref 150-450), reticulocytes 4% (ref 0.77-2.36). Erythropoietin was 55.9 mIU/mL (ref 2.6-18.5), and ferritin was 199 mg/L (ref 11-307). The clinician ordered a bone marrow biopsy and myeloproliferative neoplasm workup. The following calreticulin variant was identified by fragment analysis (Figure 1) and next generation sequencing (Figure 2).
Jadee Neff, M.D., Ph.D.
Fellow, Molecular Genetic Pathology
Rong He, M.D.
Consultant, Division of Hematopathology
Assistant Professor of Laboratory Medicine and Pathology
Mayo Clinic College of Medicine and Sciences