Higher Risk of Autism Spectrum Disorder Found in PWS Children

More than 70% of children and adolescents with Prader-Willi syndrome (PWS) have a high risk of developing autism spectrum disorder (ASD), according to a study in Chinese patients.

The findings also indicated that individuals who were shorter, had excess weight, and experienced obstructive sleep apnea — a condition in which the airways become constricted during sleep, a common problem in PWS — were at a higher risk of developing ASD.

The study, “Early Screening and Risk Factors of Autism Spectrum Disorder in a Large Cohort of Chinese Patients With Prader-Willi Syndrome,” was published in the journal Frontiers in Psychiatry and was conducted by scientists in China and the U.S.

PWS is caused by the loss of a set of paternal genes in chromosome 15 that normally control sleep, metabolism, appetite, and food intake.

Previous studies reported that up to 40% of patients with PWS also have ASD, a neurodevelopmental disorder characterized by repetitive behaviors and deficits in social communication. Yet, the small number of patients enrolled in these studies, along with the fact they did not include those with milder and broader symptoms, challenged these findings.

“The early identification and screening of individuals with PWS that are at risk for ASD will help facilitate early intervention, which can significantly impact their prognosis, thus highlighting the need for further studies,” the researchers wrote.

Here, they reported the findings of a study that aimed to identify children and adolescents with PWS who were at a high risk of developing ASD, based on the scores of two screening tools commonly used to identify people with autistic traits. At the same time, they also sought to identify ASD risk factors in these patients.

A total of 218 children and adolescents with a genetically confirmed diagnosis of PWS were recruited to participate in the study through the PWS Care & Support Center in Zhejiang, China.

The Ages and Stages Questionnaires, 3rd Edition (ASQ-3) was used to screen for developmental and behavioral abnormalities in the 113 children, younger than 3 years, who participated in the study. Those scoring “monitor” or “fail” in the communication domain of ASQ-3 were classified as being at high risk of developing ASD.

The Gilliam Autism Rating Scale, 3rd Edition (GARS-3) was used for the remaining 105 older children, ages 3–18, to screen for the presence of autistic features. In this scale, those scoring 71–100 (level 2) or more (level 3) in the Autistic Index were considered to be at high risk of developing ASD.

Results showed that 77.9% of children under 3 and 83.8% of those 3–18 were classified as being at high risk of developing ASD.

The percentages in both age groups were much higher compared with ASD cases reported previously, which may be due to the fact that earlier studies did not account for milder forms of autism that were also included in these analyses, the scientists wrote.

“These two measurements [ASQ-3 and GARS-3] were selected not only because they are age … appropriate for our two age groups, but also because they best serve our aims of early screening in this survey study,” the investigators wrote. “Thus, we believe that our results from these screening methods are generalizable to the early screening of those with [milder ASD] in PWS patients.”

Statistical analyses also found that in the group of children, 3 and older, those who were shorter, carried excess weight, or had obstructive sleep apnea were at a higher risk of having ASD.

“These risk factors and their internal relationship with ASD or ASD traits warrant further studies,” the team added.