According to the researchers, the findings have implications for treatment and intervention.
Both Prader-Willi and Angelman syndrome are neurodevelopmental disorders that are associated with intellectual disabilities in patients.
Most PWS patients are within the mild IQ range, while those with Angelman syndrome usually have severe intellectual abnormalities. Also, Prader-Willi children are characterized by social difficulties that lie along the autism spectrum disorder (ASD) continuum.
Certain gene abnormalities leading to PWS and Angelman syndrome lie within genetic regions that are also thought to be associated with autism spectrum disorder. Exploring the details of this association would be useful in devising autism-specific interventions.
In the study, “Exploring autism symptoms in an Australian cohort of patients with Prader-Willi and Angelman syndromes,” published in the Journal of Neurodevelopmental Disorders, researchers aimed to investigate the association between autism spectrum disorder (ASD) and Prader-Willi and Angelman syndrome.
The study included 25 Prader-Willi and 19 Angelman syndrome patients (ages 1-39). All patients had confirmed genetic abnormalities on chromosome 15, which has genetic regions associated with ASD.
Intellectual abilities were assessed using standard scales, and autism symptoms were assessed using the Autism Diagnostic Observation Schedule-2nd Edition (ADOS-2).
In terms of intellectual abilities, the Prader-Willi group had higher scores compared to the Angelman syndrome group. However, the PWS group also had significantly higher autism-related scores.
Researchers also described Prader-Willi patients as having more difficulties in social communication, while Angelman syndrome patients were “motivated to engage socially with others.”
“PWS present with more global social communication difficulties … while those with [Angelman syndrome] may present with difficulties on particular items due to other comorbidities associated with [Angelman syndrome],” researchers wrote.
“In particular, motor deficits associated with [Angleman syndrome] may impair the individual’s ability to point, gesture and show items to others,” they noted.
Although the study is limited by the few number of patients included, it still is one of the largest studies of its kind in Prader-Willi and Angelman syndrome patients.
Overall, the team concluded that “PWS cases presented with greater symptoms associated with ASD compared to individuals with [Angelman syndrome]. Mental health issues associated with PWS may contribute to elevated symptoms of ASD, particularly in adolescents and adults with PWS.”
The researchers believe that these findings are important since they may have implications for treatment and intervention in both Prader-Willi and Angelman patients.