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Genetics Home Reference: your guide to understanding genetic conditions
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LDHB

Reviewed February 2012

What is the official name of the LDHB gene?

The official name of this gene is “lactate dehydrogenase B.”

LDHB is the gene's official symbol. The LDHB gene is also known by other names, listed below.

What is the normal function of the LDHB gene?

The LDHB gene provides instructions for making a protein called lactate dehydrogenase-B, which is one piece (subunit) of the lactate dehydrogenase enzyme. There are five different forms of this enzyme, each made up of four protein subunits. Various combinations of lactate dehydrogenase-B subunits and lactate dehydrogenase-A subunits (which are produced from a different gene) make up the different forms of the enzyme. The lactate dehydrogenase enzyme, which is found throughout the body, is important for creating energy for cells. The simple sugar glucose is the energy source for most cells. In the final step of glucose breakdown, most forms of the lactate dehydrogenase enzyme convert the molecule pyruvate into a similar molecule called lactate, which can be used by the body for energy. Other forms of this enzyme can convert lactate back to pyruvate, which can participate in other chemical reactions to create energy.

The version of lactate dehydrogenase made of four lactate dehydrogenase-B subunits is found primarily in heart (cardiac) muscle. This version of the enzyme converts lactate to pyruvate.

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

lactate dehydrogenase deficiency - caused by mutations in the LDHB gene

More than 15 mutations in the LDHB gene have been found to cause lactate dehydrogenase deficiency, specifically lactate dehydrogenase-B deficiency. This condition is associated with a decrease in functional lactate dehydrogenase enzyme, but it does not appear to cause any physical signs or symptoms. Most LDHB gene mutations change single protein building blocks (amino acids) in the lactate dehydrogenase-B subunit. LDHB gene mutations lead to the production of an abnormal lactate dehydrogenase-B subunit that cannot form the lactate dehydrogenase enzyme. Even though lactate dehydrogenase activity is decreased in cardiac muscle cells of people with lactate dehydrogenase-B deficiency, they do not appear to have any signs or symptoms related to their condition. It is unclear why this type of enzyme deficiency does not cause any health problems.

Where is the LDHB gene located?

Cytogenetic Location: 12p12.2-p12.1

Molecular Location on chromosome 12: base pairs 21,635,340 to 21,657,970

The LDHB gene is located on the short (p) arm of chromosome 12 between positions 12.2 and 12.1.

The LDHB gene is located on the short (p) arm of chromosome 12 between positions 12.2 and 12.1.

More precisely, the LDHB gene is located from base pair 21,635,340 to base pair 21,657,970 on chromosome 12.

See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.

Where can I find additional information about LDHB?

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

  • lactate dehydrogenase H chain
  • LDH-B
  • LDHBD
  • LDHB_HUMAN
  • LDH-H
  • LDH heart subunit
  • L-lactate dehydrogenase B chain

See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.

What glossary definitions help with understanding LDHB?

acids ; breakdown ; cardiac ; deficiency ; dehydrogenase ; enzyme ; gene ; glucose ; lactate ; molecule ; muscle cells ; protein ; simple sugar ; subunit

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://ghr.nlm.nih.gov/glossary).

References

  • OMIM: LACTATE DEHYDROGENASE B (http://omim.org/entry/150100)
  • Maekawa M, Kanno T. Laboratory and clinical features of lactate dehydrogenase subunit deficiencies. Clin Chim Acta. 1989 Dec 15;185(3):299-308. (http://www.ncbi.nlm.nih.gov/pubmed/2620460?dopt=Abstract)
  • NCBI Gene (http://www.ncbi.nlm.nih.gov/gene/3945)
  • Okumura N, Terasawa F, Ueno I, Oki K, Yamauchi K, Hidaka H, Tozuka M, Okura M, Katsuyama T. Genetic analyses in homozygous and heterozygous variants of lactate dehydrogenase-B (H) subunit--LD-B Matsumoto I and II (LD-B W323R). Clin Chim Acta. 1999 Sep;287(1-2):163-71. (http://www.ncbi.nlm.nih.gov/pubmed/10509905?dopt=Abstract)
  • Sudo K, Maekawa M, Kanno T, Li SS, Akizuki S, Magara T. Premature termination mutations in two patients with deficiency of lactate dehydrogenase H(B) subunit. Clin Chem. 1994 Aug;40(8):1567-70. (http://www.ncbi.nlm.nih.gov/pubmed/8044998?dopt=Abstract)

 

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? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

 
Reviewed: February 2012
Published: January 27, 2015