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


Reviewed April 2013

What is the official name of the FLT4 gene?

The official name of this gene is “fms-related tyrosine kinase 4.”

FLT4 is the gene's official symbol. The FLT4 gene is also known by other names, listed below.

What is the normal function of the FLT4 gene?

The FLT4 gene provides instructions for making a protein called vascular endothelial growth factor receptor 3 (VEGFR-3), which regulates the development and maintenance of the lymphatic system. The lymphatic system produces and transports fluids and immune cells throughout the body. VEGFR-3 is turned on (activated) by two proteins called vascular endothelial growth factor C (VEGF-C) and vascular endothelial growth factor D (VEGF-D). When VEGF-C and VEGF-D attach (bind) to VEGFR-3, chemical signals are produced that regulate the growth, movement, and survival of lymphatic cells.

Does the FLT4 gene share characteristics with other genes?

The FLT4 gene belongs to a family of genes called immunoglobulin superfamily, immunoglobulin-like domain containing (immunoglobulin superfamily, immunoglobulin-like domain containing). It also belongs to a family of genes called immunoglobulin superfamily, I-set domain containing (immunoglobulin superfamily, I-set 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 FLT4 gene related to health conditions?

Milroy disease - caused by mutations in the FLT4 gene

At least 19 mutations in the FLT4 gene have been found to cause Milroy disease. Most mutations in this gene change a single protein building block (amino acid) in regions known as tyrosine kinase domains. Mutations in these regions disrupt VEGFR-3 signaling and cause the tubes that carry lymph fluid (lymphatic vessels) to be small or absent. If lymph fluid is not properly transported, it builds up in the body's tissues and causes swelling (lymphedema). It is not known how mutations in the FLT4 gene lead to the other signs and symptoms of Milroy disease.

Where is the FLT4 gene located?

Cytogenetic Location: 5q35.3

Molecular Location on chromosome 5: base pairs 180,601,505 to 180,650,270

The FLT4 gene is located on the long (q) arm of chromosome 5 at position 35.3.

The FLT4 gene is located on the long (q) arm of chromosome 5 at position 35.3.

More precisely, the FLT4 gene is located from base pair 180,601,505 to base pair 180,650,270 on chromosome 5.

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

Where can I find additional information about FLT4?

You and your healthcare professional may find the following resources about FLT4 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 FLT4 gene or gene products?

  • FLT41
  • vascular endothelial growth factor receptor 3
  • VEGFR3

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

What glossary definitions help with understanding FLT4?

amino acid ; gene ; growth factor ; kinase ; lymph ; lymphatic system ; lymphedema ; protein ; receptor ; tyrosine ; vascular

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


  • Brice G, Child AH, Evans A, Bell R, Mansour S, Burnand K, Sarfarazi M, Jeffery S, Mortimer P. Milroy disease and the VEGFR-3 mutation phenotype. J Med Genet. 2005 Feb;42(2):98-102. Review. (
  • Butler MG, Dagenais SL, Rockson SG, Glover TW. A novel VEGFR3 mutation causes Milroy disease. Am J Med Genet A. 2007 Jun 1;143A(11):1212-7. (
  • Evans AL, Bell R, Brice G, Comeglio P, Lipede C, Jeffery S, Mortimer P, Sarfarazi M, Child AH. Identification of eight novel VEGFR-3 mutations in families with primary congenital lymphoedema. J Med Genet. 2003 Sep;40(9):697-703. (
  • Gene Review: Milroy Disease (
  • Irrthum A, Karkkainen MJ, Devriendt K, Alitalo K, Vikkula M. Congenital hereditary lymphedema caused by a mutation that inactivates VEGFR3 tyrosine kinase. Am J Hum Genet. 2000 Aug;67(2):295-301. Epub 2000 Jun 9. (
  • Karkkainen MJ, Ferrell RE, Lawrence EC, Kimak MA, Levinson KL, McTigue MA, Alitalo K, Finegold DN. Missense mutations interfere with VEGFR-3 signalling in primary lymphoedema. Nat Genet. 2000 Jun;25(2):153-9. (
  • NCBI Gene (


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: April 2013
Published: March 23, 2015