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Start free with EleplanCrigler-Najjar syndrome type 1
ORPHA:79234Clinical subtype
Also called Bilirubin uridinediphosphate glucuronosyltransferase deficiency type 1 · Bilirubin-UGT deficiency type 1
What it is
A form of Crigler Najjar syndrome (CNS), a hereditary disorder of hepatic bilirubin conjugation, characterized by severe neonatal unconjugated hyperbilirubinemia due to a complete absence of hepatic UDP-glucuronosyltransferase 1A1. The disorder clinically manifests with neonatal, isolated, severe and permanent jaundice with a permanent risk of bilirubin encephalopathy.
Key facts
- Age of onset
- Neonatal
- Inheritance
- Autosomal recessive
- Classified as
- Clinical subtype
Recorded for the broader condition
- Prevalence
- 1-9 / 100 000 (Europe)Crigler-Najjar syndrome
Orphanet records these for the broader condition rather than for this specific form. They are a starting point, not a figure for this subtype — subtypes often differ, and some are defined by being rarer than the condition they sit under.
Signs and symptoms
Very common80–99%
7These 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
ICD-10 codes
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
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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