Cookies help us deliver our services. By using our services, you agree to our use of cookies. Learn more

Non-Ketotic Hyperglycinemia

What is Non-Ketotic Hyperglycinemia?

Non-Ketotic Hyperglycinemia is a rare autosomal recessive metabolic disorder characterized by abnormally high levels of the amino acid glycine.


Non-Ketotic Hyperglycinemia is a rare autosomal recessive metabolic disorder characterized by abnormally high levels of the amino acid glycine.
Acknowledgement of Non-Ketotic Hyperglycinemia has not been added yet.
Synonyms for Non-Ketotic Hyperglycinemia has not been added yet.
Non-Ketotic Hyperglycinemia is caused by a shortage of the enzyme that normally breaks down glycine in the body. An autosomal recessive metabolic disorder caused by deficiencies in the mitochondrial GLYCINE cleavage system; an enzyme system with four components: P-, T-, H-, and L-proteins. Deficiency of the P-protein is the most prevalent form. Neonatal and juvenile presentations have been reported. Neonatal onset is more common and may be fatal. Both parents are carriers of the gene.
There are several symptoms that affect people with Non-Ketotic Hyperglycinemia.
Name Description
Listlessness Listlessness
Spasticity Spasticity
Seizures Seizures
Involuntary muscle contractions Involuntary muscle contractions
Opisthotonos Opisthotonos
Hiccups Hiccups
Apnea Apnea
Failure to thrive Failure to thrive
Mental retardation Mental retardation
Progressive spastic diplegia Progressive spastic diplegia in late onset form
Optic atrophy Optic atrophy in late onset form
Convulsions Convulsions
Poor feeding Poor feeding
Vomiting Vomiting
High level of glycine High level of glycine in urine, in plasma, and in cerebrospinal fluid.
Reduced muscle tone Reduced muscle tone
1.Diagnostic elevated levels of glycine in the plasma, cerebral spinal fluid (CSF), and urine high CSF/plasma glycine ratio deficiency of the hepatic glycine cleavage enzyme system activity on samples collected by liver biopsy prenatal deficiency of the enzyme system activity in cultured chorionic villi 2. Serum some organic acidemias can cause hyperglycinemia (i.e., propionic and methylmalonic acidemias) and should be ruled out by serum and urine amino acid and organic acid determinations normal serum pH with no ketoacidosis 3. EEG diffusely abnormal hypsarrhythmia and/or burst-suppression pattern may be present 4. CT/MRI cerebral atrophy delayed myelination
Diagnostic tests of Non-Ketotic Hyperglycinemia has not been added yet
1. Supportive: multidisciplinary approach Pediatrics, Neurology, PT genetic counseling, P/T, O/T, speech therapy 2. Medical: Convert Glycine to an Excretable Compound a. Sodium Benzoate conjugates with glycine and excreted as hippuric acid reduces both plasma and CSF glycine concentrations clinical benefit more apparent in milder form of the disease b. Dextromethorphan (DM) glycine accumulation in the CNS may stimulate N-methyl-D-asparate (NMDA) receptors leading to increased excitatory activity with subsequent impairment of neuronal functions and synaptic development DM is a NMDA receptor antagonist and may diminish certain neurological manifestations c. Anticonvulsant Therapy indicated 3. Diet: protein restriction may be indicated
Patients usually die in the newborn period. Those that survive the newborn period are usually severely mentally impaired with seizures and spasticity if not treated medically. Some patients can learn to hold their head up, sit, walk, communicate, and eat orally. All children are affected to varying degrees of disabilities and abilities.
Tips or Suggestions of Non-Ketotic Hyperglycinemia has not been added yet.
References of Non-Ketotic Hyperglycinemia has not been added yet.
hello Created by dhalia
Last updated 1 Jul 2011, 09:59 AM

Posted by Northwest
1 Jul 2011, 09:59 AM

Hi Dhalia, I'm really sorry to hear about your little girl being diagnosed with NKH. We have a 15month old son who also has NKH, he was diagnosed at 8 days old and has the very severe form although he does now feed by mouth, cries when he us unhappy and hits toys that are near him. He has a few fits a day although some days he has none at all. Is your little girl on medication? There is a great support network, the NKH network and Judy Clifford will put you in touch with other families who might live near you. It's really hard because like you, we just don't know what the future holds for our son but all we can do is make him as comfortable as we can and enjoy every day we have with him. All the best and let me know if you have any questions.

Posted by dhalia
30 Jun 2011, 07:05 AM

I'm new here... My first and only child was recently diagnosed with non-ketotic hyperglycinemia. She's 7-month-old and I'm very affraid of what is going to happen. Please, I would like to know how others cope with this...

hi all Created by nkhmom1
Last updated 8 Jun 2010, 01:48 PM

Posted by Lwyde
8 Jun 2010, 01:48 PM

not sure how to use this site yet, but trying to figure it out

Posted by nkhmom1
16 Dec 2008, 02:40 AM

Hey its missy from ohio. Ryan Miller's mom. if anyone is on here let me know. hope everyone has a great holiday. Missy

Hi Created by Rachel
Last updated 21 Feb 2009, 06:01 PM

Posted by Judy
21 Feb 2009, 06:01 PM

Hi...feel free to email me at and ask away. Also you can join our website at to read the message board or sign up to be able to post questions or replys. ~Judy

Community External News Link
Title Date Link
Community Resources
Title Description Date Link
NKH International Family Network

We are a parental run support group where we offer information & guidance to those who have/had a child with NKH.


Clinical Trials

Cords registry

CoRDS, or the Coordination of Rare Diseases at Sanford, is based at Sanford Research in Sioux Falls, South Dakota. It provides researchers with a centralized, international patient registry for all rare diseases. This program allows patients and researchers to connect as easily as possible to help advance treatments and cures for rare diseases. The CoRDS team works with patient advocacy groups, individuals and researchers to help in the advancement of research in over 7,000 rare diseases. The registry is free for patients to enroll and researchers to access.

Enrolling is easy.

  1. Complete the screening form.
  2. Review the informed consent.
  3. Answer the permission and data sharing questions.

After these steps, the enrollment process is complete. All other questions are voluntary. However, these questions are important to patients and their families to create awareness as well as to researchers to study rare diseases. This is why we ask our participants to update their information annually or anytime changes to their information occur.

Researchers can contact CoRDS to determine if the registry contains participants with the rare disease they are researching. If the researcher determines there is a sufficient number of participants or data on the rare disease of interest within the registry, the researcher can apply for access. Upon approval from the CoRDS Scientific Advisory Board, CoRDS staff will reach out to participants on behalf of the researcher. It is then up to the participant to determine if they would like to join the study.

Visit to enroll.

Community Leaders


Expert Questions

Ask a question

Community User List

Hello, <p>&nbsp;</p> <p>&nb...
I'm a mother to 7-month-old...
I am a speech/language path...
My daughter Emily was born ...
Identical twin sons, Mark &...
I have a 14 yr old son who ...
Mum to NKH Angel, Heather.
great gdson has this disease
I am the mother of a deceas...
I am 19 years old. I was b...
Hello! <p>&nbsp;</p> <p>&nb...
I have 2 grandson's.Dylan w...
I'm a young mother from Rom...
I am greatly blessed with 6...
I have three kids one that ...
I have two daughters, ages ...
I have a daughter born with...
I have a child with Non-ket...

Start a Community

Don't See Your Condition On Rareshare?

Start your own! With a worldwide network of 8,000 users, you won't be the only member of your community for long.


Have questions about rareshare?

Visit our Frequently Asked Questions page to find the answers to some of the most commonly asked questions.

Discussion Forum


Created by dhalia | Last updated 1 Jul 2011, 09:59 AM

hi all

Created by nkhmom1 | Last updated 8 Jun 2010, 01:48 PM


Created by Rachel | Last updated 21 Feb 2009, 06:01 PM


Our Communities

Join Rareshare to meet other people that have been touched by rare diseases. Learn, engage, and grow with our communities.


Our Resources

Our rare disease resources include e-books and podcasts





Our Community Leaders

Community leaders are active users that have been touched by the rare disease that they are a part of. Not only are they there to help facilitate conversations and provide new information that is relevant for the group, but they are there for you and to let you know you have a support system on Rareshare.