Addressing Underdiagnosis; Search & Rescue Australia

Thank you to data compiled and published through the National Disability Insurance Scheme (NDIS) we have been able to confirm what we had suspected, that compared to the estimated prevalence (often cited as 1:15,000*) up to 75% of Australians are not properly diagnosed. 

There are currently 509 individuals identified as diagnosed with AS in Australia under the age of 65**, 47% live in the greater Melbourne, Sydney, and Brisbane areas, and 30% of individuals live in areas classified as Regional*. If prevalence rates are correct, there should be approximately 1700 individuals in Australia. We anticipate underdiagnosis is likely due to two or more factors, lack of understanding of the syndrome and lack of access to testing before 2000.

AS is caused by a loss of function in the UBE3A gene on the maternal 15th chromosome. There are different mechanisms (genotypes) that can cause AS that all involve the UBE3A gene, a deletion of the gene is the most common. Mutation, Uniparental Disomy, Imprinting Centre defects and mosaicism can also cause AS; While certain features are present in all affected children, there is great variability across genotypes making the syndrome difficult to characterise if you have not seen, or have only seen a few individuals.

Tim is 32 years old and was diagnosed when he was 15. I remember the day I found out that he had AS. I was driving home from holidays when a call came through from Monash Genetics Clinic telling me that Tim was positive for AS and that it was a mutation.
We had been told for 13 years that he had Autism, something that I felt wasn’t quite right. After convincing our Neurologist to test him for AS, even though he was sure it wasn’t that, the result came back positive. The neurologist still didn’t believe it, so he had bloods tested again. Came back positive.
About 10 minutes after the initial call, another one came through to ask if we could attend the Angelman Conference in Sydney.
We couldn’t believe that there was a possibility of a ‘cure’, thank goodness for that conference because at least we had hope.
The conference blew us away with the amount of research being done and it was great to see other Angelman families and to know we were not alone.” ~ Julie Rose

Spearheaded by FAST US, in collaboration with the Global Angelman Syndrome Registry, FAST Search & Rescue aims to identify all individuals around the globe living with Angelman syndrome. This global initiative is supported by dozens of international affiliates and a team of esteemed national and international clinicians and experts in diagnostics and genetics.

We’re also exploring partnerships with other stakeholders who represent rare conditions and organisations to address underdiagnosis, particularly among adults with developmental delays who may have been first diagnosed with autism. Alongside this, we are developing strategies to raise awareness and better communicate testing availability and pathways as well as variability across the syndrome.

It is incredibly important for us to communicate the significance of diagnosis as it directly correlates with granting access to Angelman Syndrome Standards of Care. We must dispel the notion that “labels don’t matter” and instead underscore that treating symptoms effectively hinges on accurate diagnosis. Given the promising interim results from numerous clinical trials, access to ongoing trials and any future approved therapeutics is contingent upon a diagnosis of Angelman syndrome.

**The population prevalence of AS is estimated at 1:12,000-1:24,000 [Mertz et al 2013].

Feasibility of Screening for Chromosome 15 Imprinting Disorders in 16 579 Newborns by Using a Novel Genomic Workflow [Godler et al 2022].

**NDIS data Mar24. *NDIS data supplied Sept23.