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MAP3K1 gene

mitogen-activated protein kinase kinase kinase 1

Normal Function

The MAP3K1 gene provides instructions for making a protein that helps regulate signaling pathways that control various processes in the body, including the processes of determining sex characteristics before birth. The MAP3K1 protein attaches (binds) to other molecules called RHOA, MAP3K4, FRAT1, and AXIN1. The binding of MAP3K1 to these molecules, which are called cofactors, helps MAP3K1 control the activity of the signaling pathways.

Health Conditions Related to Genetic Changes

Swyer syndrome

Variants (also called mutations) in the MAP3K1 gene are thought to account for up to 18 percent of cases of Swyer syndrome, also known as 46,XY complete gonadal dysgenesis or 46,XY pure gonadal dysgenesis. Swyer syndrome is a condition that affects sex development. 

Sex development usually follows a particular pattern based on an individual's chromosomes. People usually have 46 chromosomes in each cell. Two of the 46 chromosomes, known as X and Y, are called sex chromosomes because they help determine whether a person will develop male or female sex characteristics. Girls and women typically have two X chromosomes (46,XX karyotype), while boys and men typically have one X chromosome and one Y chromosome (46,XY karyotype). However, individuals with Swyer syndrome have a male-typical chromosome pattern (46,XY karyotype), but they develop female-typical sex characteristics. 

The MAP3K1 gene variants that cause Swyer syndrome result in production of MAP3K1 proteins that attach to cofactors more readily than usual. Enhanced binding reduces signaling that leads to male-typical sex development and increases signaling that leads to female-typical sex development. As a result, affected individuals with a 46,XY karyotype will not develop male gonads (testes) but will develop female reproductive structures (a uterus and fallopian tubes).

More About This Health Condition

Breast cancer

MedlinePlus Genetics provides information about Breast cancer

More About This Health Condition

Langerhans cell histiocytosis

MedlinePlus Genetics provides information about Langerhans cell histiocytosis

More About This Health Condition

Other disorders

MAP3K1 gene variants have also been identified in people with 46,XY disorder of sex development, which is also known as partial gonadal dysgenesis. These variants likely have similar but less severe effects on signaling pathways involved in sex development than those that cause Swyer syndrome (described above). Affected individuals may have external genitalia that do not look clearly male or clearly female or other abnormalities of the genitals and reproductive organs.

Other Names for This Gene

  • M3K1_HUMAN
  • MAP/ERK kinase kinase 1
  • MAPK/ERK kinase kinase 1
  • MEK kinase 1
  • MEKK
  • MEKK 1
  • MEKK1
  • mitogen-activated protein kinase kinase kinase 1, E3 ubiquitin protein ligase
  • SRXY6

Additional Information & Resources

Tests Listed in the Genetic Testing Registry

Scientific Articles on PubMed

Gene and Variant Databases


  • Jara L, Gonzalez-Hormazabal P, Cerceno K, Di Capua GA, Reyes JM, Blanco R, Bravo T, Peralta O, Gomez F, Waugh E, Margarit S, Ibanez G, Romero C, Pakomio J, Roizen G. Genetic variants in FGFR2 and MAP3K1 are associated with the risk of familial and early-onset breast cancer in a South-American population. Breast Cancer Res Treat. 2013 Jan;137(2):559-69. doi: 10.1007/s10549-012-2359-z. Epub 2012 Dec 7. Citation on PubMed
  • Loke J, Pearlman A, Radi O, Zuffardi O, Giussani U, Pallotta R, Camerino G, Ostrer H. Mutations in MAP3K1 tilt the balance from SOX9/FGF9 to WNT/beta-catenin signaling. Hum Mol Genet. 2014 Feb 15;23(4):1073-83. doi: 10.1093/hmg/ddt502. Epub 2013 Oct 16. Citation on PubMed
  • Nelson DS, van Halteren A, Quispel WT, van den Bos C, Bovee JV, Patel B, Badalian-Very G, van Hummelen P, Ducar M, Lin L, MacConaill LE, Egeler RM, Rollins BJ. MAP2K1 and MAP3K1 mutations in Langerhans cell histiocytosis. Genes Chromosomes Cancer. 2015 Jun;54(6):361-8. doi: 10.1002/gcc.22247. Epub 2015 Mar 31. Citation on PubMed
  • Pearlman A, Loke J, Le Caignec C, White S, Chin L, Friedman A, Warr N, Willan J, Brauer D, Farmer C, Brooks E, Oddoux C, Riley B, Shajahan S, Camerino G, Homfray T, Crosby AH, Couper J, David A, Greenfield A, Sinclair A, Ostrer H. Mutations in MAP3K1 cause 46,XY disorders of sex development and implicate a common signal transduction pathway in human testis determination. Am J Hum Genet. 2010 Dec 10;87(6):898-904. doi: 10.1016/j.ajhg.2010.11.003. Citation on PubMed or Free article on PubMed Central
  • Zheng Q, Ye J, Wu H, Yu Q, Cao J. Association between mitogen-activated protein kinase kinase kinase 1 polymorphisms and breast cancer susceptibility: a meta-analysis of 20 case-control studies. PLoS One. 2014 Mar 4;9(3):e90771. doi: 10.1371/journal.pone.0090771. eCollection 2014. Citation on PubMed or Free article on PubMed Central

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.