Caring for someone with this diagnosis? Eleplan keeps diagnoses, medications, documents and every specialist in one plan.
Start free with EleplanChristianson syndrome
ORPHA:85278Malformation syndrome
Also called X-linked Angelman-like syndrome
What it is
A rare developmental defect during embryogenesis characterized by intellectual deficit, ataxia, postnatal microcephaly, and hyperkinesis.
Key facts
- Prevalence
- 1-9 / 100 000
- Age of onset
- Infancy, Neonatal
- Inheritance
- X-linked recessive
- Classified as
- Malformation syndrome
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%
29- Abnormal repetitive mannerisms
- Abnormal thorax morphology
- Adducted thumb
- Aplasia/Hypoplasia of the corpus callosum
- Autism
- Cerebellar atrophy
- Cerebral cortical atrophy
- Conspicuously happy disposition
- Constipation
- Delayed gross motor development
- Drooling
- Dysphagia
- EEG abnormality
- Failure to thrive
- Feeding difficulties
- Feeding difficulties in infancy
- Gait ataxia
- Gastroesophageal reflux
- Hyperkinetic movements
- Inappropriate laughter
- Microcephaly
- Mutism
- Nystagmus
- Open mouth
- Ophthalmoplegia
- Pectus excavatum
- Secondary microcephaly
- Seizure
- Ventriculomegaly
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.
Powered by Eleplan
A rare diagnosis is just the start. Eleplan keeps the whole care plan in one place.
Diagnoses, medications, documents, appointments, and the whole care team — organized and always in sync, so you are not retelling the same story to every new specialist. With Ellie, your AI care assistant, on top of it. Free to start.