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Genetics Home Reference: your guide to understanding genetic conditions     A service of the U.S. National Library of Medicine®

SDR gene family

Reviewed May 2012

What are the SDR genes?

Genes in the SDR family provide instructions for making enzymes called short-chain dehydrogenases/reductases (SDRs). These enzymes have a variety of functions that include breaking down (metabolizing) several substances in the body, such as hormones, chemical messenger molecules called prostaglandins, substances similar to vitamin A known as retinoids, fats (lipids), and medications or other foreign chemicals (xenobiotics). To get the energy to carry out their functions, SDR enzymes use one of two molecules called NADP(H) or NAD(H), which are known as cofactors because they help carry out the enzyme's chemical reactions.

There are more than 70 SDR genes in humans. These genes are classified into five subfamilies based on their gene sequence, what substances their protein products break down, and which cofactors these proteins use.

Mutations in SDR genes are associated with a variety of disorders. Many of these disorders are caused by an inability to break down a particular substance. For example, mutations in the HSD3B2 and HSD17B3 genes disrupt normal hormone processing and lead to abnormal sexual development. Impaired lipid breakdown due to mutations in the NSDHL gene cause limb abnormalities and skin problems in CHILD syndrome.

Which genes are included in the SDR gene family?

The HUGO Gene Nomenclature Committee (HGNC) provides an index of gene families ( and their member genes.

Genetics Home Reference summarizes the normal function and health implications of these members of the SDR gene family: GALE, HSD3B2, HSD3B7, HSD17B3, HSD17B4, HSD17B10, NSDHL, QDPR, and SPR.

What conditions are related to genes in the SDR gene family?

Genetics Home Reference includes these conditions related to genes in the SDR gene family:

  • 17-beta hydroxysteroid dehydrogenase 3 deficiency
  • 17β-hydroxysteroid dehydrogenase type 10 deficiency
  • 3-beta-hydroxysteroid dehydrogenase deficiency
  • congenital bile acid synthesis defect type 1
  • congenital hemidysplasia with ichthyosiform erythroderma and limb defects
  • D-bifunctional protein deficiency
  • dopa-responsive dystonia
  • galactosemia
  • Perrault syndrome
  • sepiapterin reductase deficiency
  • tetrahydrobiopterin deficiency

Where can I find additional information about the SDR gene family?

You may find the following resources about the SDR gene family helpful.

  • SDR: Short-Chain Dehydrogenases/Reductases (

What glossary definitions help with understanding the SDR gene family?

breakdown ; dehydrogenase ; enzyme ; galactose ; gene ; hormone ; lipid ; lipid breakdown ; oxidoreductase ; prostaglandins ; protein ; reductases ; retinoids ; syndrome ; xenobiotics

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


These sources were used to develop the Genetics Home Reference summary for the SDR gene family.

  • Kallberg Y, Oppermann U, Jörnvall H, Persson B. Short-chain dehydrogenases/reductases (SDRs). Eur J Biochem. 2002 Sep;269(18):4409-17. (
  • Persson B, Kallberg Y, Bray JE, Bruford E, Dellaporta SL, Favia AD, Duarte RG, Jörnvall H, Kavanagh KL, Kedishvili N, Kisiela M, Maser E, Mindnich R, Orchard S, Penning TM, Thornton JM, Adamski J, Oppermann U. The SDR (short-chain dehydrogenase/reductase and related enzymes) nomenclature initiative. Chem Biol Interact. 2009 Mar 16;178(1-3):94-8. doi: 10.1016/j.cbi.2008.10.040. Epub 2008 Nov 5. (
  • Kallberg Y, Oppermann U, Persson B. Classification of the short-chain dehydrogenase/reductase superfamily using hidden Markov models. FEBS J. 2010 May;277(10):2375-86. doi: 10.1111/j.1742-4658.2010.07656.x. (


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: May 2012
Published: February 1, 2016