Recent research led by Mount Sinai’s Seaver Autism Center reveals that Phelan-McDermid syndrome (PMS), a rare genetic disorder closely tied to autism, could be far more prevalent than once believed, with an estimated 1 in 7,300 people affected.
- Phelan-McDermid syndrome affects about 1 in 7,300 people.
- Thousands of cases likely go undiagnosed due to limited genetic testing.
- Advances in treatment are stimulating clinical trials based on genetics.
What happened
Scientists at the Seaver Autism Center collaborated with genetic testing labs, medical centers, and autism researchers to analyze genetic data from nearly 180,000 individuals with autism. By combining findings from multiple sources and accounting for undiagnosed cases, the team estimated PMS affects roughly 13.7 people per 100,000, or about 1 in 7,300 individuals. This prevalence estimate is significantly higher than past figures suggested, pointing to a larger population living with this genetic syndrome than previously recognized.
Phelan-McDermid syndrome results from a deletion or mutation in the SHANK3 gene on chromosome 22, which plays an important role in brain development and function. People with PMS often experience intellectual disabilities, medical issues, and behavioral challenges. Most meet criteria for autism spectrum disorder, with SHANK3 mutations accounting for an estimated one percent of autism cases. Despite this, many individuals remain undiagnosed because genetic testing is not routinely offered or insurance barriers limit access.
Why it feels good
This new understanding brings hope to families and clinicians by shedding light on a previously under-recognized cause of autism and developmental disabilities. Identifying PMS more accurately allows for more tailored medical care and support, connecting individuals to specialized resources and interventions that can improve quality of life. It confirms the suspicions held by many advocates that a significant number of people have not yet been diagnosed.
Importantly, the timing is encouraging as several potential treatments are now moving into clinical trials. Scientific advances in understanding the genetic basis of PMS are enabling precision medicine approaches that target the underlying biology of the disorder. This means that a diagnosis is no longer just explanatory, but could soon open doors to therapies that modify disease progression and improve outcomes.
What to enjoy or watch next
Moving forward, experts recommend that every child diagnosed with autism should undergo comprehensive genetic testing, emphasizing that knowledge gained can be empowering and life-changing. As PMS becomes more commonly recognized, watch for expanded access to genetic diagnostics and increased inclusion of PMS patients in clinical research studies. These developments can accelerate discovery and refine treatments tailored to this population's needs.
Anticipate further updates on therapeutic breakthroughs stemming from these genetic insights within the next five years. Advocacy groups, researchers, and pharmaceutical companies are joining forces to bring effective interventions from lab to clinic. Families affected by PMS can also look forward to growing support networks and resources designed specifically to assist them in navigating medical, educational, and social challenges.