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HSD17B4

HSD17B4

Reviewed December 2014

What is the official name of the HSD17B4 gene?

The official name of this gene is “hydroxysteroid (17-beta) dehydrogenase 4.”

HSD17B4 is the gene's official symbol. The HSD17B4 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 HSD17B4 gene?

The HSD17B4 gene provides instructions for making the D-bifunctional protein. This protein is an enzyme, which means that it helps specific biochemical reactions take place. D-bifunctional protein is so named because it aids in two biochemical reactions.

The D-bifunctional protein is found in sac-like cell structures (organelles) called peroxisomes, which contain a variety of enzymes that break down many different substances. The D-bifunctional protein is involved in the breakdown of certain molecules called fatty acids. The protein has two separate regions (domains) with enzyme activity, called the hydratase and dehydrogenase domains. These domains help carry out the second and third steps, respectively, of a process called the peroxisomal fatty acid beta-oxidation pathway. This process shortens the fatty acid molecules by two carbon atoms at a time until the fatty acids are converted to a molecule called acetyl-CoA, which is transported out of the peroxisomes for reuse by the cell.

Does the HSD17B4 gene share characteristics with other genes?

The HSD17B4 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 HSD17B4 gene related to health conditions?

D-bifunctional protein deficiency - caused by mutations in the HSD17B4 gene

More than 60 HSD17B4 gene mutations have been identified in individuals with D-bifunctional protein deficiency, a severe disorder that causes deterioration of nervous system functions (neurodegeneration) beginning in infancy. HSD17B4 gene mutations that cause D-bifunctional protein deficiency can affect one or both of the enzymatic activities of D-bifunctional protein; however, this distinction does not seem to affect the severity or features of the disorder.

Impairment of one or both of the D-bifunctional protein's enzymatic activities prevents it from breaking down fatty acids efficiently. As a result, these fatty acids accumulate in the body. It is unclear how fatty acid accumulation leads to the specific features of D-bifunctional protein deficiency; however, the accumulation may result in abnormal development of the brain and the breakdown of myelin, which is the covering that protects nerves and promotes the efficient transmission of nerve impulses. Destruction of myelin leads to a loss of myelin-containing tissue (white matter) in the brain and spinal cord; loss of white matter is described as leukodystrophy. Abnormal brain development and leukodystrophy likely underlie the neurological abnormalities that occur in D-bifunctional protein deficiency.

Perrault syndrome - caused by mutations in the HSD17B4 gene

At least two HSD17B4 gene mutations have been found to cause Perrault syndrome, a condition characterized by hearing loss in affected males and females and ovarian abnormalities in affected females. The HSD17B4 gene mutations involved in this condition reduce the amount of functional D-bifunctional protein that is produced. It is not known what effect these mutations have on fatty acid breakdown in affected individuals or how the mutations lead to the signs and symptoms of Perrault syndrome.

Where is the HSD17B4 gene located?

Cytogenetic Location: 5q21

Molecular Location on chromosome 5: base pairs 119,452,442 to 119,542,334

The HSD17B4 gene is located on the long (q) arm of chromosome 5 at position 21.

The HSD17B4 gene is located on the long (q) arm of chromosome 5 at position 21.

More precisely, the HSD17B4 gene is located from base pair 119,452,442 to base pair 119,542,334 on chromosome 5.

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

Where can I find additional information about HSD17B4?

You and your healthcare professional may find the following resources about HSD17B4 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 HSD17B4 gene or gene products?

  • 3-alpha,7-alpha,12-alpha-trihydroxy-5-beta-cholest-24-enoyl-CoA hydratase
  • 17beta-estradiol dehydrogenase type IV
  • 17-beta-HSD 4
  • 17-beta-HSD IV
  • 17-beta-hydroxysteroid dehydrogenase 4
  • beta-hydroxyacyl dehydrogenase
  • beta-keto-reductase
  • D-3-hydroxyacyl-CoA dehydratase
  • D-bifunctional protein, peroxisomal
  • DBP
  • MFE-2
  • MPF-2
  • multifunctional protein 2
  • peroxisomal multifunctional enzyme type 2
  • peroxisomal multifunctional protein 2
  • PRLTS1
  • SDR8C1
  • short chain dehydrogenase/reductase family 8C, member 1

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 HSD17B4?

acids ; breakdown ; cell ; CoA ; deficiency ; dehydrogenase ; enzyme ; fatty acids ; gene ; leukodystrophy ; molecule ; nervous system ; neurological ; ovarian ; oxidation ; peroxisomes ; protein ; syndrome ; tissue ; white matter

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

See also Understanding Medical Terminology.

References (7 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.

 
Reviewed: December 2014
Published: December 22, 2014