Phelan McDermid Syndrome (pms) Prevalence Tracker
POPULATION PREVALENCE ESTIMATE
13.7
per
100,000
Approximately 45,000
1 in ~7,300
individuals have PMS in U.S.
95% CONFIDENCE INTERVAL
10.02 - 18.60 per 100,000
(1 in ~10,000 to 1 in ~5,400)
HOW THE ESTIMATE WAS DERIVED
Data sources
The study team reached out to clinical genetic testing laboratories, research centers, and clinical centers.
Data collected
Sites provided the number of PMS diagnoses made out of the total number of participants with autism tested at their site.
Adjustments made
Further extrapolations were made to adjust for the proportion of individuals with PMS who do not have autism, autism diagnosis age limitations, and type of genetic variant.
Population extrapolation
The Centers for Disease Control and Prevention (CDC) estimates of autism prevalence rates were used to extrapolate to the general population.
Final estimate
After applying extrapolations, including adjustments for assay sensitivity and other factors, the final weighted average was 13.7 per 100,000.
STUDY DETAILS
Sources participating
10
Autism cases evaluated
179,837
Frequency of PMS diagnosis among autism cases
1% to ~2.5%
(Raw results varied by testing method and should not be directly compared.)
Study Design
Population-based prevalence estimation study
Population represented
General population (via extrapolation from autism rates)
This project was funded by Neuren Pharmaceuticals, CureSHANK and Seaver Autism Center.
Key Findings
This population-based study found PMS to affect approximately 13.7 per 100,000 individuals (1 in ~7,300), with a 95% CI of 10.02-18.60 per 100,000 (1 in ~10,000 to 1 in ~5,400), substantially higher than previous estimates of 2.5-10 per million births (0.25-1 per 100,000). Phelan-McDermid syndrome is a rare genetic condition caused by deletion or mutation of the SHANK3 gene on chromosome 22.
Read the Landmark Prevalence Study Announcement
Learn more about the landmark study estimating that Phelan-McDermid syndrome may affect approximately 1 in 7,300 people, why the findings matter, and what they mean for families, researchers, and the future of precision medicine.
Read the Full Announcement →