Online Articles: Clinical and Laboratory ObservationsManagement of a Patient With Congenital Biallelic CSF3R Mutation With GM-CSFYilmaz Karapinar, Deniz MD*; Özdemir, Hamiyet Hekimci MD*; Akinci, Burcu MD*; Yaşar, Akkiz Şahin MD*; Siviş, Zuhal Önder MD*; Onay, Hüseyin MD†; Özkinay, Ferda MD†Author Information Departments of *Pediatric Hematology †Medical Genetics, Faculty of Medicine, Ege University, Izmir, Turkey The authors declare no conflict of interest. Reprints: Deniz Yilmaz Karapinar, MD, Department of Pediatric Hematology, Faculty of Medicine, Ege University, Izmir 35040, Turkey (e-mail: firstname.lastname@example.org). Received June 26, 2018 Accepted October 22, 2018 Journal of Pediatric Hematology/Oncology: April 2020 - Volume 42 - Issue 3 - p e164-e166 doi: 10.1097/MPH.0000000000001359 Buy Metrics Abstract Severe Congenital Neutropenia (SCN) is a rare inherited disease characterized by an absolute neutrophil count (ANC) lower than 500/μL. Genetic heterogeneity and biallelic CSF3R mutation has rarely been identified as an underlying genetic defect in SCN. The majority of SCN patients respond to granulocyte colony stimulating factor treatment; however, in patients with inherited CSF3R mutation, ANC cannot generally be increased with granulocyte colony stimulating factor treatment. In such cases, granulocyte macrophage colony stimulating factor presents as an effective treatment option. Herein, we report a case of a 5-year-old SCN girl with homozygous c610-611 del ins AG (p.Q204R) mutation in the CSF3R gene, who was successfully treated with granulocyte macrophage colony stimulating factor. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.