3-beta-hydroxysteroid dehydrogenase deficiency ..., (3-hydroxysteroid dehydrogenase deficiency beta) - Gen HSD3B2
Deficiency 3-beta-hydroxysteroid dehydrogenase (3?-HSD) is an inherited disorder that affects some hormone - producing glands, including the gonads and adrenal glands. Gonads result in direct sexual development before birth and during puberty. Adrenals, regulate the production of certain hormones and control of the salt concentrations in the body. People with 3?-HSD deficiency lack many of the hormones that are synthesized in these glands. This disease is one of a group of disorders known as congenital adrenal hyperplasia, which affect the production of some hormones and development and sexual maturation.
There are three types of 3?-HSD deficiency: which involves loss of salt, which does not cause loss of salt and nonclassical types. In the type of salt loss, hormone production is extremely low. People with this type lose large amounts of sodium in the urine, which can be life threatening. Usually in those affected with the type of salt loss, the disease is diagnosed shortly after birth due to complications related to the lack of reabsorption of salt, such as dehydration, lack of appetite and vomiting. People with type that does not cause loss of salt, encode sufficient hormone to allow sodium reabsorption in kidney. People with type nonclassical have milder symptoms of all types and suffer no loss of salt.
In men with some sort of 3?-HSD deficiency, problems with male sex hormones cause abnormal external genitals. These anomalies ranging from hypospadias to ambiguous genitalia. Due to dysfunction of the hormone in the testes, males 3?-HSD deficiency are often infertile. Meanwhile, women with 3?-HSD deficiency may have slight abnormalities of the external genitalia at birth. Women affected with loss rates salt or non - classical, usually are not diagnosed until mid childhood or puberty, when they have irregular menstruation and premature pubic hair growth and / or hirsutism. In general, women with 3?-HSD deficiency are infertile.
This process is due to mutations in the gene HSD3B2, located on the short arm of chromosome 1 (1p13.1), which encodes the enzyme 3?-HSD is located in the gonads and adrenal glands. The 3?-HSD enzyme is involved in the synthesis of many hormones such as cortisol, aldosterone, androgens and estrogens. Cortisol has many functions, such as maintaining energy levels and blood sugar, protecting the body from stress and inflammation. Aldosterone is sometimes called the salt - retaining hormone because it regulates the amount of salt retained by the kidney. Salt retention affects fluid levels and blood pressure. Androgens and estrogens are essential for normal sexual development and reproduction.
They have identified at least 37 mutations in the gene HSD3B2 in people with 3?-HSD deficiency. Most of these mutations change the amino acid 3?-HSD enzyme, reducing the enzyme activity. Mutations that allow the encoding of some functional enzymes, although in low concentrations, causes the body to lose less severe forms salt or non - classical forms of deficiency 3?-HSD. Other mutations result encoding an abnormally short and completely non - functional enzyme, which causes the most severe form (type salt loss) of this disease. All types of 3?-HSD deficiency interfere with coding a variety of hormones and lead to developmental abnormalities and sexual maturation.
This disease is inherited in an autosomal recessive pattern, that is, both copies of the gene in every cell must have mutations for alteration is expressed. The parents of an individual with an autosomal recessive disease have a copy of the mutated gene, but usually show no signs and symptoms of the disease.
Tests in IVAMI: in IVAMI perform detection of mutations associated with deficiency of 3-beta-hydroxysteroid dehydrogenase, by complete PCR amplification of the exons of the gene HSD3B2, and subsequent sequencing.
Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).