Disease Directory Angelman Syndrome
Neurological

Angelman Syndrome

Also known as: AS, UBE3A deficiency, happy puppet syndrome (historical), chromosome 15q11-q13 deletion

Prevalence

1-5 per 10,000 (Orphanet)

Onset

Infantile, Childhood

Type

Genetic (imprinting disorder, deletion or UBE3A mutation)

Gene

UBE3A

About Angelman Syndrome

Angelman syndrome is a neurodevelopmental disorder caused by loss of function of the maternally inherited UBE3A gene on chromosome 15q11-q13. The paternal copy of UBE3A is normally silenced in neurons by imprinting, so loss of the maternal copy results in absence of UBE3A protein in the brain. Characteristic features include severe intellectual disability, absence of speech, happy demeanor with frequent laughter, movement disorder, seizures, and microcephaly.

Common Clinical Features

Absence of speech Intellectual disability Happy, sociable demeanor Seizures (often EEG-distinctive) Ataxic gait Microcephaly Sleep disturbance

Clinical Trial Eligibility Tips

What to know before applying to Angelman Syndrome trials.

Molecular subtype (deletion, UPD, imprinting defect, UBE3A mutation) critically determines trial eligibility — antisense oligonucleotide (ASO) trials typically target non-deletion cases

Chromosome 15 methylation analysis and FISH/microarray results are required documentation for most trials

Vineland Adaptive Behavior Scales and EEG are standard baseline measures for trial enrollment

Seizure status and current antiseizure medications must be stable for a defined period before enrollment

Patient Resources

Patient Organization

Angelman Syndrome Foundation

Visit website ↗

Natural History Registry

Global Angelman Syndrome Registry

Join registry ↗

Orphanet

European reference resource for rare diseases (ORPHA:72)

View on Orphanet ↗

NORD

National Organization for Rare Disorders

Search NORD ↗

Find recruiting Angelman Syndrome trials

Search 500,000+ studies from ClinicalTrials.gov, filtered for Angelman Syndrome. Updated daily.

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