RecruitingPhase 1 / Phase 2NCT06662188
Neurological
Phelan-McDermid Syndrome
Also known as PMS, 22q13.3 deletion syndrome, SHANK3 haploinsufficiency
Phelan-McDermid syndrome is caused by deletion of 22q13.
ORPHA:48652 ↗Gene SHANK3Prevalence 1-9 per 100,000 (Orphanet)Onset Neonatal, InfantileGenetic (chromosomal deletion or SHANK3 mutation, usually de novo)
3
studies recruiting now
as of 7 Sept 2026
21
studies registered in total
as of 7 Sept 2026
2
countries with a recruiting site
as of 7 Sept 2026
18 May 2026
most recent study posted
among recruiting studies
Recruiting trials
RecruitingPhase 3NCT07281079
A Study of NNZ-2591 in Pediatric Participants With Phelan-McDermid Syndrome
RecruitingPhase 3NCT07593391
An Open-label Study of NNZ-2591 in Pediatric Participants With Phelan-McDermid Syndrome
Showing the 3 most recently updated recruiting studies, as recorded 7 Sept 2026. Live status on each study page.
Search all Phelan-McDermid Syndrome studiesWhere recruiting studies are running
Countries with at least one recruiting site among the studies above, 7 Sept 2026. Tap a country to search trials there.
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Registry: PMS Foundation International Registry · Join ↗. Registries connect patients to researchers and often hear about trials first.
About Phelan-McDermid Syndrome
Phelan-McDermid syndrome is caused by deletion of 22q13.3 or point mutations in SHANK3, encoding a scaffolding protein at glutamatergic synapses critical for synapse formation and plasticity. Clinical features include severe intellectual disability, absent or severely delayed speech, global developmental delay, neonatal hypotonia, autism spectrum features, minor dysmorphic features, and absent or minimal pain perception. Insulin-like growth factor 1 (IGF-1) and intranasal insulin have been studied as potential treatments.
Common clinical features
Absent or severely limited speechSevere intellectual disabilityAutism spectrum featuresNeonatal hypotoniaAbsent pain responseSeizures (50%)Minor dysmorphic features
From Orphanet’s phenotype annotations (CC BY 4.0). Not a complete list.
Before you apply
Things trial teams commonly ask about for Phelan-McDermid Syndrome. Not eligibility rules; those are set by each study.
- 22q13.3 deletion size or specific SHANK3 variant must be documented — deletion size correlates with phenotype severity and affects trial eligibility
- Autism diagnostic measures (ADOS-2, ADI-R) are standard baseline tools alongside adaptive behavior scales
- IGF-1 and insulin trials require baseline metabolic and IGF-1 level documentation
- Regression episodes (loss of previously acquired skills, often with fever) should be tracked and documented — regression history affects eligibility
Related conditions
Information, not medical advice. Trial listings are shown as recorded on ClinicalTrials.gov; whether any study is right for you is a decision for you and your clinicians, and eligibility is decided by each research team. Disease information from Orphanet (CC BY 4.0).