Living with Phelan-McDermid syndrome
A genetic condition from a missing piece of chromosome 22 with developmental delay, low muscle tone, and little or no speech.
Understanding Phelan-McDermid syndrome
Features vary widely. They include developmental delay, intellectual disability, low muscle tone, and absent or delayed speech. Some people have autism spectrum traits. Many have a reduced ability to sweat, which can increase the risk of overheating, and a lower sensitivity to pain. Seizures and loss of skills can occur less often.
Signs & symptoms
Symptoms vary from person to person. GARD lists these among the most common:
- Delayed or absent speech
- Low muscle tone (hypotonia)
- Autistic behavior
- Reduced sweating
- Less sensitivity to pain
- Trouble sleeping and feeding
Not everyone has every symptom. GARD's list comes from the Human Phenotype Ontology.
Diagnosis
- 1Talk with your doctor
Share the symptoms you've noticed, when they started and your family health history. Notes and photos can help.
- 2See a specialist
Specialists who may be involved include brain and nervous system specialists, genetic specialists and skin, hair, and nail specialists.
- 3Consider genetic testing
Changes in SHANK3 are linked to this condition. Genetic testing and counseling can help confirm a diagnosis and explain what it means for your family.
Care & treatment
- Care team
- Brain and nervous system specialists (neurologists); Genetic specialists (geneticists); Skin, hair, and nail specialists (dermatologists)
- Expert care
- Ask about multidisciplinary care centers for rare conditions
- Treatment
- GARD doesn't list specific treatments for this condition. Your care team will tailor care to your symptoms.
- Research
- Clinical trials and observational studies may be options. See the research section below.
General information, not medical advice. Your care team makes the decisions.
Everyday life
Living with a rare condition is easier with support.
- Connect with Phelan-McDermid Syndrome Foundation and other patient organizations
- Keep notes on symptoms, changes and questions for appointments
- Ask about patient registries that help research
- Look into financial aid and travel resources for care visits
Quick facts
Changes in the SHANK3 gene cause this condition, usually from the loss of a small piece of chromosome 22. GARD lists it as autosomal dominant.
Also known as: 22q13.3 deletion; 22q13.3 deletion syndrome; monosomy 22q13; monosomy 22q13.3; phelan mcdermid syndrome; phmds
Patient organizations
- Phelan-McDermid Syndrome FoundationPhelan-McDermid syndrome · United States
- Chromosome Disorder OutreachPhelan-McDermid syndrome · United States
- CureSHANKPhelan-McDermid syndrome · United States
- Children's Skin Disease FoundationSkin diseases · United States
You are more than your diagnosis
Perspectives from people navigating life with Phelan-McDermid syndrome.
Explore research for Phelan-McDermid syndrome
Explore actively recruiting Phelan-McDermid syndrome studies with HealthSpark.
Find actively recruiting studies for Phelan-McDermid syndrome with HealthSpark. Share your city to explore research near you.
- Recruiting studies from ClinicalTrials.gov
- Share your city to look for research near you
- Eligibility is confirmed by the study team
Powered by HealthSpark, our AI chat helper
I can help you find recruiting Phelan-McDermid syndrome studies. Enter a ZIP code, address or city below and I'll look within 50 miles.
Powered by HealthSpark, our AI chat helper · Study information from ClinicalTrials.gov · Eligibility is confirmed by the study team.
Get Signals for Phelan-McDermid syndrome
Stay in the loop with community stories and updates from medical researchers.
Create a living journal that talks back
HealthStory evolves private journaling with a living AI journal that talks back and asks thoughtful questions, helping you capture your Phelan-McDermid syndrome experiences more deeply and prepare for better conversations with your doctors and care team.
Your journal is private. Sharing your story publicly is a separate choice, made with Share your story above.