If you are a professional or carer working with Angelman Syndrome we aim to support you with up to date information on research and clinical developments. Our resources include:

Angelman Syndrome an overview

Angelman Syndrome an overview

AS Infographic

Types of Angelman Syndrome Explained

75% Deletion

The majority of AS cases are caused by deletions on the maternal copy of Chromosome 15. This deletion prevents the normal expression of a gene called UBE3A in individuals with AS.

10%  UBE3A mutation

Mutations in the UBE3A gene either prevent its expression or function. Thus these individuals do not have the appropriate levels of functional UBE3A in the brain.

7 % Uniparental Disomy

In UPD, the individual has two copies of paternal Chromosome 15. Because UBE3A is not expressed from the paternal copy, these individuals lack normal levels of UBE3A in the brain.

5% Clinical/Other

In these individuals, all testing for Angelman Syndrome is normal, but they still meet the diagnostic criteria for AS. Please note that there are several other syndromes that present like AS that can be tested for

3%  Imprinting defect These individuals may have a deletion of the imprinting centre an Chromosome 15. Loss of imprinting will prevent expression of the maternal UBE3A gene in the brain.

NOTE: The National  Centre for Medical Genetics  Ireland also provides a comprehensive explanation of the current testing methods for this  chromosome disorder


Timeline of Angelman Syndrome

Timeline of Angelman Syndrome


1965 –   Dr Harry Angelman publishes a report entitled “Puppet Children” about 3 children he observed.

1980’s – Research into AS begins in University of Florida under the direction of Dr Charles Williams

1982 Name changed from ‘Happy Puppet’ to Angelman Syndrome

1987 Discovery that absent genetic code on maternal Chromosome 15 is the genetic marker for AS

1997 The cause of AS discovered by Dr. Joseph Wagstaff & Dr. Arthur Beaudet  mutation or deletion of UBE3A gene

2007   Neurological deficits can be reversed in a mouse model with AS

2011 Dr Ben Philpot discovers how to “switch on” the silent paternal genetic code on

Chromosome 15 in a mouse

2012  Dr Ed Weeber begins clinical trials with 24 children using Minocycline to treat cognition and motor function

The Future Hope Is in our Genes.