Skip to content

6 Pyruvoyl Tetrahydrobiopterin Synthase Deficiency C0878676

Published: July 22, 2026Updated: August 27, 2026

A metabolic disorder affecting neurotransmitter production, caused by deficiency of a specific enzyme. Requires careful dietary management and medication.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 27, 2026Editorial policy

Key facts at a glance

ICD-10
E88.9
ICD-11
5A00.0
Body system
metabolic
Severity
severe
Chronic
true

Signs and symptoms

Common signs and symptoms that may indicate this condition.

Warning signs - seek immediate care

!

Seizures

Recurrent seizure activity due to abnormal brain electrical activity from neurotransmitter deficiency.

Seek emergency care immediately for any seizure lasting more than 5 minutes or if seizures recur.

!

Temperature Instability

Difficulty maintaining normal body temperature, often presenting as recurrent fevers or hypothermia.

Seek immediate medical attention for unexplained high fevers or persistent temperature abnormalities.

Global Developmental Delay

(neurologic)

Significant delays in reaching developmental milestones such as sitting, walking, and speaking due to impaired neurotransmitter synthesis.

Frequency: 90-100% of patients

Hypotonia

(neurologic)

Abnormally low muscle tone resulting in floppy extremities and poor head control in infants.

Frequency: 85-95% of patients

Feeding Difficulties

(gastrointestinal)

Poor feeding, refusal to eat, or difficulty with sucking and swallowing due to neurological involvement.

Frequency: 60-80% of patients

Eczema

(dermatologic)

Chronic inflammatory skin condition causing red, itchy, and scaly patches, often appearing in early infancy.

Frequency: 30-50% of patients

Microcephaly

(neurologic)

Abnormally small head circumference due to impaired brain development during gestation and early infancy.

Frequency: 40-60% of patients

Movement Disorder

(neurologic)

Involuntary movements such as dystonia, chorea, or tremor due to basal ganglia dysfunction.

Frequency: 30-50% of patients

Vomiting

(gastrointestinal)

Recurrent vomiting, sometimes projectile, associated with feeding difficulties and neurological dysfunction.

Frequency: 40-60% of patients

Hyperactivity

(neurologic)

Excessive motor activity and difficulty concentrating, often resembling attention deficit hyperactivity disorder.

Frequency: 15-25% of patients

Diagnosis and tests

How this condition is diagnosed and what test results mean.

Initial screening tests

1

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

1

Combination drug regimen with regular assessment

Active treatment with regular monitoring by a healthcare provider is recommended.

medication
2

Tetrahydrobiopterin Replacement

BH4 supplementation to restore deficient neurotransmitter synthesis pathways, typically administered daily to maintain adequate levels and prevent neurological deterioration.

medication
3

Phenylalanine-Restricted Diet

Specialized medical diet limiting phenylalanine intake from natural proteins, supplemented with phenylalanine-free amino acid formulas to support normal growth and development.

dietary

Additional treatment options

Neurotransmitter Precursor Therapy

L-DOPA and 5-HTP supplementation to compensate for deficient dopamine and serotonin synthesis, reducing movement disorders and behavioral symptoms.

medication

Metabolic and Developmental Monitoring

Regular monitoring of phenylalanine levels, neurotransmitter metabolites, growth parameters, and developmental milestones to guide treatment adjustments.

monitoring

Therapeutic Drug Level Monitoring

Laboratory testing to measure BH4 levels, neurotransmitter precursors, and their metabolites to optimize dosing and ensure therapeutic efficacy.

procedure

When to seek medical help

Recognize when you need immediate medical attention.

See a doctor within 24 hours

Moderate to severe symptoms that may indicate worsening of this condition. Prompt medical evaluation is recommended.

Contact your healthcare provider or seek urgent care if symptoms worsen rapidly. Go to the emergency department for life-threatening symptoms.

Frequently asked questions

Common questions about this topic.

Q

What is 6 Pyruvoyl Tetrahydrobiopterin Synthase Deficiency C0878676?

Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]

general

Sources and references

Authoritative medical sources used to create this content.

1

Blau N, van Spronsen FJ, Levy HL. Phenylketonuria. Lancet. 2010;376(9750):1417-1427.

review2010View source →
2

Thöny B, Blau N. Mutations in the PCBD gene causing 6-pyruvoyl-tetrahydrobiopterin synthase deficiency. Hum Mutat. 1997;10(1):11-15.

review1997View source →
3

Opladen T, Hoffmann G, Blau N. An update on BH4 therapy in hyperphenylalaninemia. J Inherit Metab Dis. 2012;35(4):571-579.

review2012View source →
4

Fiege B, Blau N. Assessment of tetrahydrobiopterin (BH4) responsiveness in Austrian PKU patients. Mol Genet Metab. 2007;90(1):65-69.

clinical_trial2007View source →
5

Longo N. Disorders of tetrahydrobiopterin metabolism. Ann Neurol. 2004;55(5):598-602.

review2004View source →
6

Blau N, Thöny B, Cotton RGH, Hyland K. Disorders of tetrahydrobiopterin metabolism and their management. J Inherit Metab Dis. 2001;24(2):231-242.

review2001View source →
7

Scriver CR, Beaudet AL, Sly WS, et al, eds. The Metabolic and Molecular Bases of Inherited Disease. 8th ed. New York: McGraw-Hill; 2001.

textbook2001
8

Zurflüh MR, Zhadina M, Weng L, et al. Genomic organization of the human 6-pyruvoyl-tetrahydropterin synthase gene and mapping to chromosome 11p14.3. Genomics. 1998;53(2):184-191.

review1998View source →
9

Niederwieser A, Shintaku N, Hasler T, et al. Neonatal hyperphenylalaninemia caused by 6-pyruvoyl-tetrahydropterin synthase deficiency. Eur J Pediatr. 1986;145(4):345-350.

review1986View source →
10

Korn-Izumi Y, Narise N, Wang L, Ichinose H. Molecular characterization of 6-pyruvoyl-tetrahydropterin synthase deficiency. J Inherit Metab Dis. 2000;23(3):265-268.

Medication Comparisons

Compare medications used to treat 6 Pyruvoyl Tetrahydrobiopterin Synthase Deficiency C0878676. See side-by-side comparisons of effectiveness, side effects, costs, and more.

View Medication Comparisons

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

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 27, 2026. · Read our editorial policy