Genetic and Rare Diseases Information Center (GARD)


Other names people use for this condition
  • 1 alpha pyrroline-5-carboxylate dehydrogenase deficiency
  • Type 2 hyperprolinemia
  • Hyperprolinemia type 2
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Hyperprolinemia type 2
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I am writing to ask for some information on hyperprolinemia type 2. Do individuals with this condition have a shortened lifespan? Is there any treatment for people who have severe symptoms? Are there any clinical trials studying the use of vitamin B6?



  • What is hyperprolinemia type 2? (Back to Top)

  • Hyperprolinemia type 2 results in an excess of a particular protein building block (amino acid), called proline, in the blood. This condition generally occurs when proline is not broken down properly by the body. Hyperprolinemia type 2 causes proline levels in the blood to be 10 to 15 times higher than normal, and it also causes high levels of a related compound called pyrroline-5-carboxylate. Some people with this condition develop mild mental retardation and seizures; however, the symptoms of this disorder vary in severity among affected individuals.[1]
  • Last Reviewed: 11/3/2008

  • Do individuals with hyperprolinemia type 2 have a shortened lifespan? (Back to Top)

  • After an extensive search of the information resources available to us, we were not able to locate any information to suggest that people with hyperprolinemia type 2 have a shortened lifespan. One study of hyperprolinemia type 2 in Ireland found that most adults had normal health.[2]
  • Last Reviewed: 11/3/2008

  • Is there any treatment for people who have severe symptoms of hyperprolinemia type 2? (Back to Top)

  • There is no specific treatment for hyperprolinemia type 2, even for those individuals who experience seizures. In general, if people with hyperprolinemia type 2 have symptoms, they are usually mild and do not require treatment. If seizures are present during childhood, they tend to disappear in adulthood. Attempts to reduce the amount of proline in an affected person's diet have resulted in only modest control of proline levels in the blood and have not reduced symptoms.[3]
  • Last Reviewed: 11/3/2008

  • Are there any clinical trials studying the use of vitamin B6 to treat hyperprolinemia type 2? (Back to Top)

  • The National Institutes of Health, through the National Library of Medicine, developed ClinicalTrials.gov to provide patients, family members, and members of the public with current information on clinical research studies. No studies involving hyperprolinemia are listed at this time, but check this site often for updates.

    CRISP (Computer Retrieval of Information on Scientific Projects) is a searchable database of federally funded biomedical research projects conducted at universities, hospitals, and other research institutions. Currently, two projects listed on CRISP involve hyperprolinemia. Although these projects may not conduct studies on humans, you may want to contact the investigators to learn more. To read about these studies, click on the link above. In the "enter search terms" box, enter "hyperprolinemia" and then click "Submit Query."

    The following article discussing vitamin B6 treatment in people with hyperprolinemia type 2. An abstract is available from PubMed:
    Wang HS, Kuo MF. Vitamin B6 related epilepsy during childhood. Chang Gung Med J. 2007 Sep-Oct;30(5):396-401. 
  • Last Reviewed: 11/3/2008


References  (Back)
  1. Hyperprolinemia. Genetics Home Reference Website . June 2007 Available at: http://ghr.nlm.nih.gov/condition=hyperprolinemia. Accessed November 3, 2008.
  2. Flynn MP, Martin MC, Moore PT, Stafford JA, Fleming GA, Phang JM. . Archives of Disease in Childhood. December 1989;64(12):1699-1707. Available at: http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=2624476. November 3, 2008.
  3. Phang JM, Hu CA, Valle D. The Metabolic and Molecular Bases of Inherited Disease. In: . Disorders of proline and hydroxyproline metabolism. New York:McGraw-Hill; 2001:1821-1838

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