National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Lactate dehydrogenase B deficiency


Other Names:
Lactate dehydrogenase deficiency type B; LDH deficiency B; LDHBD
This disease is grouped under:
Lactate dehydrogenase B deficiency (LDHBD) is a condition that affects how the body breaks down sugar to use as energy in muscle cells. Unlike people with lactate dehydrogenase A deficiency, people with this condition typically do not have any signs or symptoms. It is unclear why this condition does not cause any health problems. Affected people are usually diagnosed when routine blood tests reveal reduced activity of the enzyme lactate dehydrogenase. LDHBD is caused by mutations in the LDHB gene and is inherited in an autosomal recessive manner.[1]
Last updated: 12/16/2014

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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HPO ID
Percent of people who have these symptoms is not available through HPO
Reduced lactate dehydrogenase B level 0045041
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Last updated: 7/1/2020
Lactate dehydrogenase B deficiency (LDHBD) is typically diagnosed after routine blood tests show reduced lactate dehydrogenase (LDH) activity in serum and/or red blood cells.[1] A person has LDHBD when more specific testing shows absent or decreased levels of the LDH sub-unit H(B). This means that people with LDHBD may have either complete absence of this sub-unit, or a marked deficiency of the sub-unit.[2]

We are not aware of guidelines outlining the specific levels of LDH or the sub-unit considered diagnostic for LDHBD. In one article, the levels of serum LDH that were reported in affected people ranged from 33 to 89 units per liter (U/L), with a normal range being considered 290-540 U/L.[3] However, normal value ranges often vary among different laboratories, and some labs use different measurements or test different types of samples. Therefore, people should speak with their health care provider about the meaning of their specific results.
Last updated: 12/16/2014

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • Genetics Home Reference (GHR) contains information on Lactate dehydrogenase B deficiency. This website is maintained by the National Library of Medicine.
  • The Muscular Dystrophy Association (MDA) provides information about lactate dehydrogenase deficiency. Click on the link to access this information.
  • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
    Lactate dehydrogenase
    LDH isoenzymes

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • To have this disease, how low must the levels be? See answer


  1. Lactate dehydrogenase deficiency. Genetics Home Reference. February 2012; http://ghr.nlm.nih.gov/condition/lactate-dehydrogenase-deficiency.
  2. Carol A. Bocchini. LACTATE DEHYDROGENASE B DEFICIENCY; LDHBD. OMIM. July 27, 2011; http://omim.org/entry/614128. Accessed 12/16/2014.
  3. Sudo K, Maekawa M, Houki N, Okuda T, Akizuki S, Magara T, Kawano K. A novel in-frame deletion mutation in a case of lactate dehydrogenase (LD) H subunit deficiency showing an atypical LD isoenzyme pattern in serum and erythrocytes. Clin Biochem. March, 1999; 32(2):137-141.
  4. William J Craigen and Basil T Darras. Lactate dehydrogenase deficiency. UpToDate. Waltham, MA: UpToDate; October 8, 2014; Accessed 12/16/2014.