HSD3B7

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What is the official name of the HSD3B7 gene?

The official name of this gene is “hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 7.”

HSD3B7 is the gene's official symbol. The HSD3B7 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 HSD3B7 gene?

The HSD3B7 gene provides instructions for making an enzyme called 3 beta-hydroxysteroid dehydrogenase type 7 (3β-HSD7). This enzyme is found in liver cells. It is embedded in the membrane of a cell structure called the endoplasmic reticulum, which is involved in protein processing and distribution. The 3β-HSD7 enzyme participates in the production of bile acids, which are a component of a digestive fluid called bile. Bile acids stimulate bile flow and helps absorb fats and fat-soluble vitamins. Bile acids are produced from cholesterol in a multi-step process. The 3β-HSD7 enzyme is responsible for the second step in that process, which converts 7alpha(α)-hydroxycholesterol to 7α-hydroxy-4-cholesten-3-one.

Does the HSD3B7 gene share characteristics with other genes?

The HSD3B7 gene belongs to a family of genes called SDR (short chain dehydrogenase/reductase superfamily).

A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? in the Handbook.

How are changes in the HSD3B7 gene related to health conditions?

congenital bile acid synthesis defect type 1 - caused by mutations in the HSD3B7 gene: At least 17 mutations in the HSD3B7 gene have been found to cause congenital bile acid synthesis defect type 1. This condition is characterized by cholestasis, a condition that impairs the production and release of a digestive fluid called bile from liver cells. Most of the HSD3B7gene mutations delete one or two DNA building blocks (base pairs) from the gene or replace single protein building blocks (amino acids) in the enzyme. These mutations result in production of a 3β-HSD7 enzyme with little or no function. Without enough functional 3β-HSD7 enzyme, the conversion of 7α-hydroxycholesterol to 7α-hydroxy-4-cholesten-3-one is impaired. The 7α-hydroxycholesterol instead gets converted into abnormal bile acid compounds that cannot be transported out of the liver into the intestine, where the bile acids are needed to absorb fats and fat-soluble vitamins. This impaired production and release of bile acids leads to cholestasis. As a result, cholesterol and abnormal bile acids build up in the liver and fat-soluble vitamins are not absorbed, leading to the signs and symptoms of congenital bile acid synthesis defect type 1.

Where is the HSD3B7 gene located?

Cytogenetic Location: 16p11.2

Molecular Location on chromosome 16: base pairs 30,985,109 to 30,989,151

The HSD3B7 gene is located on the short (p) arm of chromosome 16 at position 11.2.

More precisely, the HSD3B7 gene is located from base pair 30,985,109 to base pair 30,989,151 on chromosome 16.

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

Where can I find additional information about HSD3B7?

You and your healthcare professional may find the following resources about HSD3B7 helpful.

Educational resources - Information pages (2 links)
Genetic Testing Registry - Repository of genetic test information (1 link)

You may also be interested in these resources, which are designed for genetics professionals and researchers.

PubMed - Recent literature
OMIM - Genetic disorder catalog
Research Resources - Tools for researchers (3 links)

What other names do people use for the HSD3B7 gene or gene products?

3-beta-HSD VII
3 beta-hydroxy-delta 5-C27-steroid oxidoreductase
3-beta-hydroxy-Delta(5)-C27 steroid oxidoreductase
3 beta-hydroxysteroid dehydrogenase type 7
3 beta-hydroxysteroid dehydrogenase type VII
3BHS7_HUMAN
C(27)-3BETA-HSD
c(27) 3-beta-HSD
cholest-5-ene-3-beta,7-alpha-diol 3-beta-dehydrogenase
SDR11E3
short chain dehydrogenase/reductase family 11E, member 3

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 HSD3B7?

acids ; bile ; cell ; cholesterol ; congenital ; dehydrogenase ; digestive ; DNA ;endoplasmic reticulum ; enzyme ; gene ; intestine ; oxidoreductase ; protein ; soluble ; synthesis ;vitamins

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

References (5 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.