Carbamoyl-phosphate synthetase 1…

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Carbamoyl-phosphate synthetase 1 deficiency

ORPHA:147Disease

Also called CPS1 deficiency · CPS1D · Carbamoyl-phosphate synthetase I deficiency · Carbamoyl-phosphate synthetase deficiency

What it is

A rare, severe disorder of urea cycle metabolism typically characterized by either a neonatal-onset of severe hyperammonemia that occurs few days after birth and manifests with lethargy, vomiting, hypothermia, seizures, coma and death or a presentation outside the newborn period at any age with (sometimes) milder symptoms of hyperammonemia.

Key facts

Prevalence
1-9 / 1 000 000 (at birth)
Age of onset
All ages
Inheritance
Autosomal recessive
Classified as
Disease

Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.

Signs and symptoms

These ranges are how often a sign appears across everyone diagnosed, not a prediction for one person — most people have some of these and not others. Orphanet also records findings that are specifically absent in this disease; those are in the data but not listed here.

Gene

CPS1Disease-causing germline mutation(s) (loss of function)

ICD-10 codes

E72.2filed under a broader ICD-10 category — shared with 9 other rare diseases

ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.

Related health topics

Reached through the ICD-10 categories this disease is filed under, so these describe the broader group rather than this disease specifically.

Cross-references

GARD 7269MEDDRA 10058297MESH D020165MONDO 0009376OMIM 237300UMLS C0751753

Orphadata Science: Free access data from Orphanet. © INSERM 1999. Data version 2026-06-23. Available under CC BY 4.0. This is a reference, not medical advice.

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