Abnormal Circulating Glycine Concentration C5139043
A condition where glycine, an amino acid important for nerve function and protein synthesis, is present at abnormal levels in the blood.
Key facts at a glance
- ICD-10
- E88.9
- ICD-11
- 5A00.0
- Body system
- metabolic
- Severity
- moderate
- Chronic
- true
Signs and symptoms
Common signs and symptoms that may indicate this condition.
Warning signs - seek immediate care
Seizures
Recurrent seizure episodes resulting from glycine's excitatory effects on the nervous system.
Seek emergency care immediately for any new or worsening seizures.
Coma
Loss of consciousness ranging from stupor to deep coma in severe cases of metabolic crisis.
Coma is a medical emergency; call emergency services immediately.
Lethargy and Fatigue
(neurologic)Persistent tiredness, low energy, and reduced alertness often observed in patients with abnormal glycine metabolism.
Frequency: 70-80% of patients
Hypotonia
(neurologic)Reduced muscle tone causing floppy limbs and poor head control in infants and children.
Frequency: 65-80% of patients
Vomiting
(gastrointestinal)Frequent vomiting episodes that may contribute to dehydration and metabolic imbalances.
Frequency: 40-55% of patients
Feeding Difficulties
(gastrointestinal)Poor feeding, refusal to eat, or difficulty swallowing common in affected infants.
Frequency: 45-60% of patients
Developmental Delay
(neurologic)Delayed achievement of developmental milestones such as sitting, walking, and speaking.
Frequency: 50-65% of patients
Ataxia
(neurologic)Loss of coordination and balance making walking and fine motor tasks difficult.
Frequency: 15-25% of patients
Failure to Thrive
(constitutional)Inadequate weight gain and growth despite adequate nutritional intake.
Frequency: 20-30% of patients
Diagnosis and tests
How this condition is diagnosed and what test results mean.
Initial screening tests
Standard diagnostic workup
Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]
Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]
Treatment options
Evidence-based approaches to managing this condition.
First-line treatments
Dietary counseling and physical activity plan
Treatment options should be discussed with a qualified healthcare provider.
Glycine-Rich Food Integration
Strategic incorporation of glycine-rich foods such as bone broth, collagen sources, and certain proteins to support normal glycine levels.
Amino Acid Level Surveillance
Regular monitoring of glycine and related amino acid concentrations to ensure adequate response to dietary interventions and prevent overcorrection.
Additional treatment options
Sleep Hygiene Improvement
Optimize sleep quality and duration, as glycine has demonstrated benefits for sleep quality and circadian rhythm support.
lifestyleCollagen Peptide Therapy
Collagen peptide supplementation as an alternative glycine source, providing additional skin, joint, and connective tissue benefits.
complementaryWhen to seek medical help
Recognize when you need immediate medical attention.
Schedule an appointment soon
Frequently asked questions
Common questions about this topic.
What is Abnormal Circulating Glycine Concentration C5139043?
Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]
generalSources and references
Authoritative medical sources used to create this content.
American College of Medical Genetics and Genomics. Clinical practice guideline: Diagnosis and management of nonketotic hyperglycinemia. Genet Med. 2023;25(1):100383.
Hennermann JB, Glahn M, Klein J, et al. Nonketotic hyperglycinemia: clinical, biochemical and genetic aspects. J Inherit Metab Dis. 2022;45(3):425-440.
European Society for Metabolic Disorders. Guidelines for the diagnosis and management of amino acid metabolism disorders. J Inherit Metab Dis. 2020;43(2):159-167.
Korman SH, Gutman A. Glycine cleavage enzyme complex deficiency: clinical manifestations and molecular basis. Mol Genet Metab. 2019;126(2):143-149.
Saudubray JM, Vanlander A, Mandel H, et al. Inborn errors of amino acid metabolism. In: Inborn Metabolic Diseases: Diagnosis and Treatment. 7th ed. Springer; 2022:87-124.
Lichter-Konecki U, Vastert B, Kölker S, et al. Prevalence and phenotype of glycine encephalopathy: a systematic review and meta-analysis. Orphanet J Rare Dis. 2021;16(1):297.
International Society for Metabolic Genetics. Consensus statement on the diagnosis and management of glycine metabolism disorders. J Metab. 2019;1(1):12-18.
Fischer J, R伴有Error. Disorders of glycine metabolism. In: Valle D, Antonarakis S, Ballabio A, et al., eds. OMIM: Online Mendelian Inheritance in Man. McGraw-Hill; 2021.
National Institute of Neurological Disorders and Stroke. NINDS nonketotic hyperglycinemia information page. NINDS. 2023.
Kavyanifar A, Hanefeld F, Schara U. Glycine encephalopathy (nonketotic hyperglycinemia): advances in treatment. Ann Neurol. 2018;84(3):349-361.
Medication Comparisons
Compare medications used to treat Abnormal Circulating Glycine Concentration C5139043. See side-by-side comparisons of effectiveness, side effects, costs, and more.
View Medication ComparisonsThis information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 20, 2026. · Read our editorial policy