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3-beta-hydroxysteroid dehydrogenase deficiency
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Reviewed February 2010
What is 3-beta-hydroxysteroid dehydrogenase deficiency?
3-beta (β)-hydroxysteroid dehydrogenase (HSD) deficiency is an inherited disorder that affects hormone-producing glands including the gonads (ovaries in females and testes in males) and the adrenal glands. The gonads direct sexual development before birth and during puberty. The adrenal glands, which are located on top of the kidneys, regulate the production of certain hormones and control salt levels in the body. People with 3β-HSD deficiency lack many of the hormones that are made in these glands. 3β-HSD deficiency is one of a group of disorders known as congenital adrenal hyperplasias that impair hormone production and disrupt sexual development and maturation.
There are three types of 3β-HSD deficiency: the salt-wasting, non-salt-wasting, and non-classic types. In the salt-wasting type, hormone production is extremely low. Individuals with this type lose large amounts of sodium in their urine, which can be life-threatening. Individuals affected with the salt-wasting type are usually diagnosed soon after birth due to complications related to a lack of salt reabsorption, including dehydration, poor feeding, and vomiting. People with the non-salt-wasting type of 3β-HSD deficiency produce enough hormone to allow sodium reabsorption in the kidneys. Individuals with the non-classic type have the mildest symptoms out of all the types and do not experience salt wasting.
In males with any type of 3β-HSD deficiency, problems with male sex hormones lead to abnormalities of the external genitalia. These abnormalities range from having the opening of the urethra on the underside of the penis (hypospadias) to having external genitalia that do not look clearly male or female (ambiguous genitalia). The severity of the genital abnormality does not consistently depend on the type of the condition. Because of the hormone dysfunction in the testes, males with 3β-HSD deficiency are frequently unable to have biological children (infertile).
Females with 3β-HSD deficiency may have slight abnormalities of the external genitalia at birth. Females affected with the non-salt-wasting or non-classic types are typically not diagnosed until mid-childhood or puberty, when they experience irregular menstruation, premature pubic hair growth, and/or have excessive body hair growth (hirsutism). Females with 3β-HSD deficiency are typically infertile.
How common is 3-beta-hydroxysteroid dehydrogenase deficiency?
The exact prevalence of 3β-HSD deficiency is unknown. At least 60 affected individuals have been reported.
What genes are related to 3-beta-hydroxysteroid dehydrogenase deficiency?
Mutations in the HSD3B2 gene cause 3β-HSD deficiency. The HSD3B2 gene provides instructions for making the 3β-HSD enzyme. This enzyme is found in the gonads and adrenal glands. The 3β-HSD enzyme is involved in the production of many hormones, including cortisol, aldosterone, androgens, and estrogen. Cortisol has numerous functions such as maintaining energy and blood sugar levels, protecting the body from stress, and suppressing inflammation. Aldosterone is sometimes called the salt-retaining hormone because it regulates the amount of salt retained by the kidney. The retention of salt affects fluid levels and blood pressure. Androgens and estrogen are essential for normal sexual development and reproduction.
3β-HSD deficiency is caused by a deficiency (shortage) of the 3β-HSD enzyme. The amount of functional 3β-HSD enzyme determines whether a person will have the salt-wasting or non-salt-wasting type of the disorder. Individuals with the salt-wasting type have HSD3B2 gene mutations that result in the production of very little or no enzyme. People with the non-salt-wasting type of this condandanition have HSD3B2 gene mutations that allow the production of some functional enzyme, although in reduced amounts.
Read more about the HSD3B2 gene.
How do people inherit 3-beta-hydroxysteroid dehydrogenase deficiency?
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
Where can I find information about diagnosis or management of 3-beta-hydroxysteroid dehydrogenase deficiency?
These resources address the diagnosis or management of 3-beta-hydroxysteroid dehydrogenase deficiency and may include treatment providers.
General information about the diagnosis and management of genetic conditions is available in the Handbook. Read more about genetic testing, particularly the difference between clinical tests and research tests.
To locate a healthcare provider, see How can I find a genetics professional in my area? in the Handbook.
Where can I find additional information about 3-beta-hydroxysteroid dehydrogenase deficiency?
You may find the following resources about 3-beta-hydroxysteroid dehydrogenase deficiency helpful. These materials are written for the general public.
You may also be interested in these resources, which are designed for healthcare professionals and researchers.
What other names do people use for 3-beta-hydroxysteroid dehydrogenase deficiency?
What if I still have specific questions about 3-beta-hydroxysteroid dehydrogenase deficiency?
Where can I find general information about genetic conditions?
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 3-beta-hydroxysteroid dehydrogenase deficiency?
adrenal glands ; aldosterone ; androgens ; autosomal ; autosomal recessive ; cell ; congenital ; deficiency ; dehydration ; dehydrogenase ; enzyme ; gene ; genitalia ; hirsutism ; hormone ; hyperplasia ; hypospadias ; infertile ; inflammation ; kidney ; menstruation ; prevalence ; puberty ; recessive ; reproduction ; sodium ; stress ; testes ; wasting
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (6 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.