|A service of the U.S. National Library of Medicine®|
On this page:
Reviewed April 2008
What is the official name of the SRD5A2 gene?
The official name of this gene is “steroid 5 alpha-reductase 2.”
SRD5A2 is the gene's official symbol. The SRD5A2 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 SRD5A2 gene?
The SRD5A2 gene provides instructions for making an enzyme called steroid 5-alpha reductase 2. This enzyme is involved in processing androgens, which are hormones that direct male sexual development. Specifically, the enzyme is responsible for a chemical reaction that converts the hormone testosterone to a more potent androgen, dihydrotestosterone (DHT), in male reproductive tissues.
Testosterone and DHT are essential for the normal development of male sex characteristics. Before birth, testosterone is responsible for the formation of internal male genitalia, including the tubes that collect sperm and carry it out of the testes (the epididymis and vas deferens) and glands that help produce semen (the seminal vesicles). DHT directs the development of the external genitalia, including the penis and scrotum, and the prostate gland. During puberty, these two hormones also play an important role in the development of male secondary sex characteristics such as the growth of facial and body hair, increased muscle mass, and deepening of the voice.
How are changes in the SRD5A2 gene related to health conditions?
Genetics Home Reference provides information about prostate cancer, which is also associated with changes in the SRD5A2 gene.
Where is the SRD5A2 gene located?
Cytogenetic Location: 2p23
Molecular Location on chromosome 2: base pairs 31,522,488 to 31,700,784
(Homo sapiens Annotation Release 107, GRCh38.p2) (
The SRD5A2 gene is located on the short (p) arm of chromosome 2 at position 23.
More precisely, the SRD5A2 gene is located from base pair 31,522,488 to base pair 31,700,784 on chromosome 2.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about SRD5A2?
You and your healthcare professional may find the following resources about SRD5A2 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 SRD5A2 gene or gene products?
See How are genetic conditions and genes named? in the Handbook.
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 SRD5A2?
acids ; acne ; alanine ; amino acid ; androgens ; cancer ; cell ; chromosome ; deficiency ; dehydrogenase ; DHT ; dihydrotestosterone ; enzyme ; epididymis ; gene ; genitalia ; hirsutism ; hormone ; hypospadias ; inherited ; leucine ; menstruation ; micropenis ; ovary ; polycystic ovary syndrome ; polymorphism ; progression ; prostate ; prostate gland ; protein ; puberty ; scrotum ; semen ; seminal vesicles ; sperm ; syndrome ; testes ; testosterone ; threonine ; tissue ; valine ; vas deferens
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (11 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.