Diagnosis and Tests

Angelman syndrome may be suspected if a child's development is delayed and they have the syndrome's distinctive characteristics.

Angelman Syndrome

Diagnosing Angelman Syndrome

Angelman syndrome may be suspected if a child's development is delayed and they have the syndrome's distinctive characteristics (see Symptoms and Types Section).

A blood sample can be taken to confirm the diagnosis. A number of genetic tests will be carried out on the sample. These may include:

  • Chromosome analysis - to see if any parts of the chromosomes are missing (deletions).
  • Fluorescence in situ hybridisation (FISH) - used to check specifically for chromosome 15 deletions when Angelman syndrome is suspected, or to check the mother's chromosomes.
  • DNA methylation - which shows whether the genetic material on both the mother's and father's chromosomes is active.
  • UBE3A gene mutation analysis - used to see if the genetic code on the maternal copy of the UBE3A gene is altered.

 

For each child with Angelman syndrome, it's important to know the genetic change that caused the condition. This helps to determine whether there's a risk of it occurring again in another child, or whether there are implications for other members of the family.

 

Most children with Angelman syndrome are diagnosed between the ages of 18 months and 6 years, when the typical physical and behavioural symptoms become apparent.

 

If your child is diagnosed with Angelman syndrome, you should be given the opportunity to discuss the genetic diagnosis and implications with a genetic doctor.