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Start free with EleplanMucolipidosis type II
ORPHA:576Disease
Also called I-cell disease · Mucolipidosis type II alpha/beta · N-acetylglucosamine 1-phosphotransferase deficiency
What it is
A rare, severe form of mucolipidosis characterized by growth retardation, skeletal abnormalities (dysostosis multiplex, craniosynostosis, contractures of the joints and osteopenia), facial dysmorphism, stiff skin, obstructive airway, cardiomegaly and severe global developmental delay.
Key facts
- Prevalence
- <1 / 1 000 000 (Europe)
- Age of onset
- Antenatal, Neonatal
- 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
Very common80–99%
13Common30–79%
16- Abnormality of the thoracic cavity
- Abnormal mitral valve morphology
- Cognitive impairment
- Conductive hearing impairment
- Craniosynostosis
- Depressed nasal bridge
- Flat face
- Inability to walk
- Limitation of joint mobility
- Mitral regurgitation
- Narrow chest
- Obstructive sleep apnea
- Otitis media
- Poor speech
- Pulmonary insufficiency
- Restrictive ventilatory defect
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
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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