What Is Phelan-McDermid Syndrome?
Phelan-McDermid Syndrome, often shortened to PMS, is most commonly associated with a deletion or variant affecting SHANK3, a gene important for synapses, the connections brain cells use to communicate. People with PMS can have developmental delay, speech and communication challenges, low muscle tone, autism features, seizures, sleep issues, gastrointestinal concerns, and a wide range of support needs.
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Plain-English explanation
Phelan-McDermid Syndrome, often shortened to PMS, is most commonly associated with a deletion or variant affecting SHANK3, a gene important for synapses, the connections brain cells use to communicate. People with PMS can have developmental delay, speech and communication challenges, low muscle tone, autism features, seizures, sleep issues, gastrointestinal concerns, and a wide range of support needs.
Why it matters
PMS is a clear example of why rare disease medicine has to connect genetics, neurology, behavior, development, family experience, and long-term care. Understanding SHANK3 biology may help therapy development, but families also need practical support now: communication, therapies, sleep care, seizure care, school planning, and community.
How it works
Diagnosis usually involves genetic testing that finds a 22q13 deletion or a pathogenic variant involving SHANK3. The size and location of a deletion can vary, and symptoms can vary widely. Research is exploring gene replacement, pathway biology, model systems, outcome measures, and clinical trial readiness, but care today remains multidisciplinary and individualized.
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