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About Angelman Syndrome

AS Genotypes: Clinical Diagnosis

Angelman Syndrome Genotypes: Clinical Diagnosis

Up to 10% of individuals who appear to have all the features of AS have negative genetic testing, meaning that methylation studies and sequencing of the UBE3A gene do not show any causes of AS.  It is important to have a clinician with expertise in genetics review the past testing and see the person who is suspected to have AS. There are other conditions that have many of the same symptoms or features as AS, so it is important that the individual is also tested for these conditions as well.  If an individual has negative genetic testing for AS and for the other conditions that can look very similar AND a clinician familiar with AS makes the diagnosis, the person may be said to have a “clinical diagnosis” of AS. It is possible that some individuals with a clinical diagnosis may have a genetic variant in UBE3A or genomic imprinting that current genetic testing methods are not able to identify or that they may have a different genetic condition that has very similar symptoms.

Because the underlying genetic cause or genotype is not known in these families, we do not know the chance for a family to have a second child diagnosed with AS.  We also do not know if the potential therapies for AS that are in clinical trials could be helpful. 

Still have questions?

If you are wondering about your specific chance to have a child with a genetic variant that causes AS, it is very important to consult a genetics professional like a genetic counselor or geneticist. The chance varies depending upon the test results of the person living with AS and the testing that was performed on the parent(s). The information provided here may be helpful but it is not specific to your family and is not meant to replace genetic counseling.

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