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Genetic and Rare Diseases Information Center (GARD)

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Hyperprolinemia type 2

Other Names for this Disease
  • 1 alpha pyrroline-5-carboxylate dehydrogenase deficiency
  • Hyperprolinemia type 2
  • Type 2 hyperprolinemia
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Your Question

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?

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

What is hyperprolinemia type 2?

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 updated: 11/1/2013

Do individuals with hyperprolinemia type 2 have a shortened lifespan?

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]  Children Living with Inherited Metabolic Diseases (CLIMB), an advocacy organization for individuals with metabolic disorders, also notes that when patients reach adulthood, they typically appear to be symptom-free. 
Last updated: 10/17/2013

How might hyperprolinemia type 2 be treated?

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 updated: 11/1/2013

Are there any clinical trials studying the use of vitamin B6 to treat hyperprolinemia type 2?

The National Institutes of Health, through the National Library of Medicine, developed 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.

The following article discusses vitamin B6 treatment in people with hyperprolinemia type 2:  Wang HS, Kuo MF. Vitamin B6 related epilepsy during childhood. Chang Gung Med J. 2007 Sep-Oct;30(5):396-401.
The full article is available at:
Last updated: 10/17/2013