steroid 5 alpha-reductase 2
Last updated 27 Oct 2023
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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.
Normal function
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.
Conditions referring to this gene or chromosome
Other names
3-oxo-5 alpha-steroid 4-dehydrogenase 2
5 alpha-SR2
MGC138457
S5A2_HUMAN
SR type 2
steroid 5-alpha-reductase 2
steroid-5-alpha-reductase, alpha polypeptide 2 (3-oxo-5 alpha-steroid delta 4-dehydrogenase alpha 2)
Type II 5-alpha reductase
Related patient information and medicines
Patient information leaflet
Enlarged prostate
See the separate leaflets called Prostate Cancer , Acute Prostatitis and Chronic Prostatitis. There are two groups of medicines that may help: Alpha-blockers. 5-alpha reductase inhibitors. This can improve the flow of urine. 5-alpha reductase inhibitor medicines. These are alternatives to alpha-blockers. These work by blocking the conversion of.
Patient information leaflet
Blood in semen
Haematospermia means there is blood in the semen. Usually there are no other symptoms such as pain. The haematospermia itself does not need any treatment. Medicines If you have persistent haematospermia without an identified cause then a type of medicine called a 5-alpha reductase inhibitor such as finasteride or dutasteride may be effective..
Patient information leaflet
Prostate problems
This leaflet will give you a brief ... There are various treatments for the symptoms of BPH, including drugs such as alfuzosin/doxazosin (alpha-blockers), dutasteride/finasteride (5-alpha reductase inhibitors), oxybutinin/tolterodine/fesoterodine/darifenacin/solifenacin/trospium (antimuscarinics), mirabegron (for overactive bladder) and.
Patient information leaflet
Ankylosing spondylitis
The type of inflammation in AS ca... Ankylosing spondylitis is an auto-immune disease. It is not known exactly why ankylosing spondylitis occurs but there is a genetic predisposition. 6 out of 100 people who have a particular gene variant called HLA-B27 have ankylosing spondylitis whereas it is thought that it affects fewer than 1 in 100 people.
Patient information leaflet
Crohn's disease
Crohn's disease is a lifelong condition with flare-ups from time to time. A course of steroids (corticosteroids) Steroid medicines work by reducing inflammation and are usually used first-line for those who are newly diagnosed or who have no more than one flare-up per year. The two commonly used steroids for Crohn's disease are budesonide and.
Patient information leaflet
Diabetes and illness
Acting quickly and following advice helps to keep your glucose levels in the normal range or only slightly high. Sick day diabetes guidelines The following guidance is provided by Diabetes UK: Contact your general practice or diabetes team who will help you if you have any queries or if you are unsure about what to do. Sick day rules diabetes type.
Further reading and references
- steroid 5 alpha-reductase 2; MedlinePlus, National Library of Medicine.
- Cicek MS, Conti DV, Curran A, Neville PJ, Paris PL, Casey G, Witte JS. Association of prostate cancer risk and aggressiveness to androgen pathway genes: SRD5A2, CYP17, and the AR. Prostate. 2004 Apr 1;59(1):69-76. doi: 10.1002/pros.10358.
- Goodarzi MO, Shah NA, Antoine HJ, Pall M, Guo X, Azziz R. Variants in the 5alpha-reductase type 1 and type 2 genes are associated with polycystic ovary syndrome and the severity of hirsutism in affected women. J Clin Endocrinol Metab. 2006 Oct;91(10):4085-91. doi: 10.1210/jc.2006-0227. Epub 2006 Jul 18.
- Kim KS, Liu W, Cunha GR, Russell DW, Huang H, Shapiro E, Baskin LS. Expression of the androgen receptor and 5 alpha-reductase type 2 in the developing human fetal penis and urethra. Cell Tissue Res. 2002 Feb;307(2):145-53. doi: 10.1007/s004410100464. Epub 2001 Nov 27.
- Makridakis N, Akalu A, Reichardt JK. Identification and characterization of somatic steroid 5alpha-reductase (SRD5A2) mutations in human prostate cancer tissue. Oncogene. 2004 Sep 23;23(44):7399-405. doi: 10.1038/sj.onc.1207922.
- Ntais C, Polycarpou A, Ioannidis JP. SRD5A2 gene polymorphisms and the risk of prostate cancer: a meta-analysis. Cancer Epidemiol Biomarkers Prev. 2003 Jul;12(7):618-24.
- Russell DW, Wilson JD. Steroid 5 alpha-reductase: two genes/two enzymes. Annu Rev Biochem. 1994;63:25-61. doi: 10.1146/annurev.bi.63.070194.000325. No abstract available.
- Salam MT, Ursin G, Skinner EC, Dessissa T, Reichardt JK. Associations between polymorphisms in the steroid 5-alpha reductase type II (SRD5A2) gene and benign prostatic hyperplasia and prostate cancer. Urol Oncol. 2005 Jul-Aug;23(4):246-53. doi: 10.1016/j.urolonc.2004.12.014.
- Sasaki G, Ogata T, Ishii T, Kosaki K, Sato S, Homma K, Takahashi T, Hasegawa T, Matsuo N. Micropenis and the 5alpha-reductase-2 (SRD5A2) gene: mutation and V89L polymorphism analysis in 81 Japanese patients. J Clin Endocrinol Metab. 2003 Jul;88(7):3431-6. doi: 10.1210/jc.2002-021415.
- Wang Y, Li Q, Xu J, Liu Q, Wang W, Lin Y, Ma F, Chen T, Li S, Shen Y. Mutation analysis of five candidate genes in Chinese patients with hypospadias. Eur J Hum Genet. 2004 Sep;12(9):706-12. doi: 10.1038/sj.ejhg.5201232.
- Wilson JD, Griffin JE, Russell DW. Steroid 5 alpha-reductase 2 deficiency. Endocr Rev. 1993 Oct;14(5):577-93. doi: 10.1210/edrv-14-5-577.
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