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Reviewed November 2008

What is the official name of the SRY gene?

The official name of this gene is “sex determining region Y.”

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

Read more about gene names and symbols on the About page.

What is the normal function of the SRY gene?

The SRY gene provides instructions for making a transcription factor called the sex-determining region Y protein. A transcription factor is a protein that attaches (binds) to specific regions of DNA and helps control the activity of particular genes. The sex-determining region Y protein causes a fetus to develop as a male.

People normally 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. Females have two X chromosomes (46,XX), and males have one X chromosome and one Y chromosome (46,XY). The SRY gene is located on the Y chromosome.

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

Swyer syndrome - caused by mutations in the SRY gene

Mutations in the SRY gene have been identified in between 15 percent and 20 percent of individuals with Swyer syndrome, also known as 46,XY complete or pure gonadal dysgenesis. SRY gene mutations that cause Swyer syndrome prevent production of the sex-determining region Y protein or result in the production of a nonfunctioning protein. A fetus whose cells do not produce functional sex-determining region Y protein will develop as a female despite having a Y chromosome.

46,XX testicular disorder of sex development - associated with the SRY gene

In most individuals with 46,XX testicular disorder of sex development, the condition results from an abnormal exchange of genetic material between chromosomes (translocation). This exchange occurs as a random event during the formation of sperm cells in the affected person's father. The SRY gene is misplaced in this disorder, almost always onto an X chromosome. A fetus with an X chromosome that carries the SRY gene will develop male characteristics despite not having a Y chromosome.

other disorders - associated with the SRY gene

SRY gene mutations that impair but do not eliminate the function of the sex-determining region Y protein have been identified in a small number of people with 46,XY disorder of sex development, or partial gonadal dysgenesis. Affected individuals may have external genitalia that do not look clearly male or clearly female (ambiguous genitalia) or other abnormalities of the genitals and reproductive organs.

About 10 percent of individuals who have both testicular and ovarian tissue, a condition called ovotesticular disorder of sex development, have two X chromosomes with one carrying the SRY gene.

Where is the SRY gene located?

Cytogenetic Location: Yp11.3

Molecular Location on the Y chromosome: base pairs 2,786,854 to 2,787,740

The SRY gene is located on the short (p) arm of the Y chromosome at position 11.3.

The SRY gene is located on the short (p) arm of the Y chromosome at position 11.3.

More precisely, the SRY gene is located from base pair 2,786,854 to base pair 2,787,740 on the Y chromosome.

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

Where can I find additional information about SRY?

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

  • essential protein for sex determination in human males
  • sex-determining region on Y
  • sex determining region protein
  • TDF
  • TDY
  • testis-determining factor

Where can I find general information about genes?

The Handbook provides basic information about genetics in clear language.

These links provide additional genetics resources that may be useful.

What glossary definitions help with understanding SRY?

cell ; chromosome ; DNA ; dysgenesis ; fetus ; gene ; genitalia ; genitals ; hermaphrodite ; ovarian ; protein ; sex chromosomes ; sex determination ; sperm ; syndrome ; testis ; tissue ; transcription ; transcription factor ; translocation

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

See also Understanding Medical Terminology.

References (10 links)


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: November 2008
Published: March 2, 2015