Test Catalog

Test ID: CSF3R    
CSF3R Exon 14 and 17 Mutation Detection by Sanger Sequencing, Varies

Useful For Suggests clinical disorders or settings where the test may be helpful

Evaluation and classification of chronic neutrophilia


Aids in the diagnosis of chronic neutrophilic leukemia (CNL)


Identification of mutations that may suggest the class of kinase inhibitor to which the neoplasm may be sensitive

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

CSF3R encodes the receptor for colony-stimulating factor 3, a cytokine that controls the production, differentiation, and function of granulocytes. Somatic CSF3R mutations were recently described in 50% to 80% of chronic neutrophilic leukemia (CNL) patients. Their association with atypical chronic myelogenous leukemia (aCML) remains controversial. They have also been reported as somatic events in severe congenital neutropenia (SCN) patients.


There are 2 types of CSF3R mutations: extracellular domain/membrane proximal point mutations (most commonly p.T618I) and cytoplasmic tail truncation mutations. They demonstrated sensitivity to JAK kinase inhibitors and Src kinase inhibitors, respectively, in in vitro assays. In CNL, the most common mutation is p.T618I, although cytoplasmic truncation mutation can also occur. Somatic cytoplasmic truncation mutations have been reported in approximately 30% of SCN patients and 80% of SCN patients with leukemic transformation, who are often on granulocyte-colony stimulating factor (GCSF) therapy. However, their role in leukemic transformation is uncertain.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

An interpretive report will be provided

Interpretation Provides information to assist in interpretation of the test results

The results will be given as positive or negative for CSF3R mutation and, if positive, the mutation will be described.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

The assay is performed using Sanger sequencing, which has a sensitivity of 20%. This means that 20% or more of the DNA in the sample must be mutated to be detected.


A positive result can be seen in chronic neutrophilic leukemia (CNL). However, it is not specific for this neoplasm and clinicopathologic correlation is necessary in all cases.


A negative result does not exclude the presence of a CNL, other myeloproliferative neoplasms, or other hematologic or nonhematologic neoplasms.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Maxson JE, Gotlib J, Pollyea DA, et al: Oncogenic CSF3R mutations in chronic neutrophilic leukemia and atypical CML. N Engl J Med 2013;368:1781-1790

2. Pardanani A, Lasho TL, Laborde RR, et al: CSF3R T618I is a highly prevalent and specific mutation in chronic neutrophilic leukemia. Leukemia 2013;27:1870-1873

3. Tefferi A, Thiele J, Vannucchi AM, et al: An overview on CALR and CSF3R mutations and a proposal for revision of WHO diagnostic criteria for myeloproliferative neoplasms. Leukemia 2014;1:1-7

4. Vandenberghe P, Beel K: Severe congenital neutropenia, a genetically heterogeneous disease group with an increased risk of AML/MDS. Pediatr Rep 2011;3(s2):e9

Special Instructions Library of PDFs including pertinent information and forms related to the test