Disease Directory Prader-Willi Syndrome
Neurological

Prader-Willi Syndrome

Also known as: PWS, chromosome 15q11-q13 paternal deletion, hypotonia-hypomentia-hypogonadism-obesity syndrome

Prevalence

1-5 per 10,000 (Orphanet)

Onset

Neonatal, Infantile

Type

Genetic (imprinting disorder, paternal deletion or maternal UPD)

Gene

SNRPN locus, MAGEL2, NDN, MKRN3 (15q11-q13 region)

About Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is caused by loss of expression of paternally inherited genes on chromosome 15q11-q13 due to paternal deletion (70%), maternal uniparental disomy (25%), or imprinting defects. Neonates present with severe hypotonia and feeding difficulties; during childhood, insatiable hyperphagia develops leading to severe obesity. Additional features include intellectual disability, hypogonadism, short stature, and behavioral problems including obsessive-compulsive traits.

Common Clinical Features

Severe neonatal hypotonia Hyperphagia and obesity Intellectual disability Hypogonadism Short stature Behavioral problems Sleep-disordered breathing

Clinical Trial Eligibility Tips

What to know before applying to Prader-Willi Syndrome trials.

Molecular subtype (deletion vs UPD vs imprinting defect) determines eligibility for some trials — chromosome 15 methylation analysis is required

BMI, hyperphagia rating scale scores, and metabolic panel are standard baseline eligibility measures

Carbetocin (intranasal oxytocin) and other hyperphagia-targeting trials typically require stable growth hormone therapy as background medication

Sleep study (polysomnography) documenting sleep-disordered breathing may be required or exclusionary

Patient Resources

Patient Organization

Prader-Willi Syndrome Association USA

Visit website ↗

Natural History Registry

PWS Global Registry

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Orphanet

European reference resource for rare diseases (ORPHA:739)

View on Orphanet ↗

NORD

National Organization for Rare Disorders

Search NORD ↗

Find recruiting Prader-Willi Syndrome trials

Search 500,000+ studies from ClinicalTrials.gov, filtered for Prader-Willi Syndrome. Updated daily.

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