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Genetics Home Reference: your guide to understanding genetic conditions     A service of the U.S. National Library of Medicine®


Reviewed January 2014

What is the official name of the FLT3 gene?

The official name of this gene is “fms related tyrosine kinase 3.”

FLT3 is the gene's official symbol. The FLT3 gene is also known by other names, listed below.

What is the normal function of the FLT3 gene?

The FLT3 gene provides instructions for making a protein called fms-like tyrosine kinase 3 (FLT3), which is part of a family of proteins called receptor tyrosine kinases (RTKs). Receptor tyrosine kinases transmit signals from the cell surface into the cell through a process called signal transduction. The FLT3 protein is found in the outer membrane of certain cell types where a specific protein called FLT3 ligand, or FL, can attach (bind) to it. This binding turns on (activates) the FLT3 protein, which subsequently activates a series of proteins inside the cell that are part of multiple signaling pathways. The signaling pathways stimulated by the FLT3 protein control many important cellular processes such as the growth and division (proliferation) and survival of cells, particularly of early blood cells called hematopoietic progenitor cells.

Does the FLT3 gene share characteristics with other genes?

The FLT3 gene belongs to a family of genes called CD (CD molecules). It also belongs to a family of genes called immunoglobulin superfamily, immunoglobulin-like domain containing (immunoglobulin superfamily, immunoglobulin-like domain containing).

A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? ( in the Handbook.

How are changes in the FLT3 gene related to health conditions?

cytogenetically normal acute myeloid leukemia - associated with the FLT3 gene

Changes in the FLT3 gene are involved in a form of blood cancer known as cytogenetically normal acute myeloid leukemia (CN-AML). While large chromosomal abnormalities can be involved in the development of acute myeloid leukemia, about half of cases do not have these abnormalities; these are classified as CN-AML.

The FLT3 gene mutations involved in CN-AML are called somatic mutations; they are found only in cells that become cancerous and are not inherited. Two types of FLT3 gene mutations are found in CN-AML. The most common, which occurs in up to 34 percent of CN-AML cases, is called the FLT3 internal tandem duplication (FLT3-ITD). In this type of mutation, a short sequence of DNA is copied and inserted directly following the original sequence. The duplicated DNA sequence can vary in size, but all FLT3-ITD mutations result in alterations in the region of the protein that spans the cell membrane, known as the juxtamembrane domain. The altered juxtamembrane domain allows the FLT3 receptor to activate signaling pathways without binding of FL; the receptor is always turned on and is said to be constitutively activated. Constant signaling leads to uncontrolled proliferation of abnormal, immature white blood cells, a hallmark of acute myeloid leukemia.

The other type of FLT3 gene mutation is found in about 14 percent of people with CN-AML. These mutations are referred to as FLT3-TKD mutations because they change single protein building blocks (amino acids) in a region of the protein known as the tyrosine kinase domain (TKD). The most commonly changed amino acid is asparagine at position 835; it is typically replaced by the amino acid tyrosine. This mutation is written as Asp835Tyr or D835Y. Like FLT3-ITD mutations, FLT3-TKD mutations result in a constitutively activated FLT3 receptor and constant signaling, leading to acute myeloid leukemia.

Where is the FLT3 gene located?

Cytogenetic Location: 13q12

Molecular Location on chromosome 13: base pairs 28,003,274 to 28,100,592

(Homo sapiens Annotation Release 107, GRCh38.p2) (NCBI (

The FLT3 gene is located on the long (q) arm of chromosome 13 at position 12.

The FLT3 gene is located on the long (q) arm of chromosome 13 at position 12.

More precisely, the FLT3 gene is located from base pair 28,003,274 to base pair 28,100,592 on chromosome 13.

See How do geneticists indicate the location of a gene? ( in the Handbook.

Where can I find additional information about FLT3?

You and your healthcare professional may find the following resources about FLT3 helpful.

You may also be interested in these resources, which are designed for genetics professionals and researchers.

What other names do people use for the FLT3 gene or gene products?

  • CD135
  • CD135 antigen
  • fetal liver kinase 2
  • FL cytokine receptor
  • FLK2
  • FLK-2
  • fms-like tyrosine kinase 3
  • fms-related tyrosine kinase 3
  • growth factor receptor tyrosine kinase type III
  • receptor-type tyrosine-protein kinase FLT3
  • stem cell tyrosine kinase 1
  • STK1
  • STK-1

See How are genetic conditions and genes named? ( in the Handbook.

What glossary definitions help with understanding FLT3?

acids ; acute ; acute myeloid leukemia ; amino acid ; AML ; asparagine ; cancer ; cell ; cell membrane ; cytokine ; DNA ; domain ; duplication ; gene ; growth factor ; hematopoietic ; inherited ; kinase ; leukemia ; ligand ; mutation ; myeloid ; progenitor cells ; proliferation ; protein ; receptor ; signal transduction ; transduction ; tyrosine ; white blood cells

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.


  • Choudhary C, Schwäble J, Brandts C, Tickenbrock L, Sargin B, Kindler T, Fischer T, Berdel WE, Müller-Tidow C, Serve H. AML-associated Flt3 kinase domain mutations show signal transduction differences compared with Flt3 ITD mutations. Blood. 2005 Jul 1;106(1):265-73. Epub 2005 Mar 15. (
  • Gilliland DG, Griffin JD. The roles of FLT3 in hematopoiesis and leukemia. Blood. 2002 Sep 1;100(5):1532-42. Review. (
  • Kiyoi H, Ohno R, Ueda R, Saito H, Naoe T. Mechanism of constitutive activation of FLT3 with internal tandem duplication in the juxtamembrane domain. Oncogene. 2002 Apr 11;21(16):2555-63. (
  • Li L, Piloto O, Kim KT, Ye Z, Nguyen HB, Yu X, Levis M, Cheng L, Small D. FLT3/ITD expression increases expansion, survival and entry into cell cycle of human haematopoietic stem/progenitor cells. Br J Haematol. 2007 Apr;137(1):64-75. (
  • NCBI Gene (
  • Yamamoto Y, Kiyoi H, Nakano Y, Suzuki R, Kodera Y, Miyawaki S, Asou N, Kuriyama K, Yagasaki F, Shimazaki C, Akiyama H, Saito K, Nishimura M, Motoji T, Shinagawa K, Takeshita A, Saito H, Ueda R, Ohno R, Naoe T. Activating mutation of D835 within the activation loop of FLT3 in human hematologic malignancies. Blood. 2001 Apr 15;97(8):2434-9. (


The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? ( in the Handbook.

Reviewed: January 2014
Published: February 8, 2016