Prader-Willi syndrome

Prader-Willi syndrome (PWS) is a multisystem genetic condition caused by absent expression of paternally active genes in chromosome region 15q11.2-q13. Feeding and growth, satiety, endocrine function, sleep and breathing, movement, learning, communication, and mental health may be affected. Needs change across the lifespan and vary by person.1

Urgent safety

Seek emergency assessment for acute abdominal swelling or pain, repeated retching or vomiting, unusual loss of appetite, marked lethargy, or a sudden major change from the person's baseline. Vomiting and pain responses can be reduced in PWS, so apparently mild symptoms may still accompany gastric dilation, inflammation, necrosis, or obstruction.1

Call emergency services for choking that does not resolve, severe breathing difficulty, blue or gray color, collapse, or reduced responsiveness. New snoring, pauses during sleep, morning headaches, daytime sleepiness, or reduced function needs prompt assessment for sleep-disordered breathing or hypoventilation.

Clinical pattern and diagnosis

Early infancy often includes hypotonia, weak suck, feeding difficulty, and slow weight gain. Later nutritional phases can include weight gain before obvious appetite change, followed by impaired satiety or hyperphagia. Developmental, learning, speech, motor, endocrine, orthopedic, vision, sleep, and mental-health features are variable.1

Hyperphagia is a biologically driven impairment of satiety, not misconduct or a failure of willpower. Anxiety, distress, rigidity, skin injury, or sudden behavior change should be assessed in context. Pain, constipation, gastric illness, sleep disruption, medication effects, change in routine, inaccessible communication, and psychiatric illness may contribute.

Diagnosis uses DNA methylation analysis of the Prader-Willi critical region, usually alongside a chromosome or SNP-based array. Further testing identifies whether the mechanism is a paternal deletion, maternal uniparental disomy, or an imprinting defect. The mechanism matters for recurrence counseling and some health risks.1

Medical care boundaries

Nutrition care should use a predictable, individualized plan developed with the person, family or supporters, and a clinician or dietitian familiar with PWS. The plan can address energy needs, nutrition, activity, food access, transitions, and distress while preserving dignity, age-appropriate autonomy, and participation. Avoid shame, surprise restriction, or using food as punishment or reward.

Diazoxide choline extended-release is FDA-approved for hyperphagia in adults and eligible pediatric patients with PWS. It is not a treatment for other PWS features and does not replace nutrition or environmental support. Hyperglycemia and fluid overload are important labeled risks, so selection and monitoring are specialist-led.1

Growth hormone can improve growth, body composition, and mobility for selected people. Endocrine review, contraindication assessment, and sleep-respiratory monitoring are part of safe use. Current guidance supports a sleep study before treatment and repeat assessment after starting or when symptoms change. Thyroid, sex-hormone, glucose, bone, and other endocrine care is individualized. Central adrenal insufficiency is not assumed from the diagnosis; testing and stress-dose steroid plans require endocrinology guidance.1

Tell the anesthesia team about PWS well before sedation, anesthesia, or surgery. Hypotonia, sleep apnea or hypoventilation, aspiration risk, body composition, temperature regulation, altered pain responses, and medicine sensitivity can change perioperative planning and monitoring. Follow a person-specific anesthesia plan rather than a universal medication or fasting protocol.4

Feeding and communication

Swallowing concerns can persist beyond infancy. Direct assessment should consider coughing or choking, prolonged meals, recurrent respiratory illness, hydration, nutrition, reflux, saliva, fatigue, positioning, and current eating pattern. Texture, pacing, equipment, supplements, and tube feeding depend on clinical and instrumental findings.1

Speech, test scores, or a PWS diagnosis do not determine understanding or decision-making capacity. Offer information in accessible steps, allow processing time, support choice and refusal, and check comprehension without infantilizing the person. Sudden communication change can be a sign of illness or distress.

AAC may combine speech, gesture, sign, writing, pictures or symbols, visual schedules, partner-assisted scanning, and speech-generating technology. Choose access from direct assessment of language, literacy, motor control, vision, hearing, fatigue, context, and preferences. Include vocabulary for consent, pain, emotions, food-related discussions, relationships, self-advocacy, and emergencies; train partners and keep a low-tech backup.5 For evaluation, trials, funding, and implementation, use the AAC device acquisition guide.

Coding

• ICD-10-CM Q87.11: Prader-Willi syndrome.6

Code associated conditions only when documented and supported by current local rules.

Sources

1. Driscoll, Miller, and Cassidy. Prader-Willi Syndrome, GeneReviews — current diagnosis, medical emergencies, endocrine care, hyperphagia treatment, and surveillance (revised 2026).
2. Shaikh et al. Prader-Willi syndrome: guidance for children and transition into adulthood — current multidisciplinary guidance for nutrition, endocrine, respiratory, developmental, and transition care.
3. US Food and Drug Administration: diazoxide choline extended-release prescribing information — approved indication, limitations, warnings, and monitoring.
4. OrphanAnesthesia: Prader-Willi syndrome recommendations — peer-reviewed condition-specific perioperative considerations.
5. American Speech-Language-Hearing Association: Augmentative and Alternative Communication — individualized, multimodal AAC assessment without prerequisites.
6. Centers for Medicare & Medicaid Services: FY2026 ICD-10-CM definitions — Q87.11 descriptor.

Review boundary

This page cannot diagnose PWS, interpret genetic results, or remotely assess abdominal, breathing, swallowing, endocrine, medication, anesthesia, mental-health, or communication safety. Emergencies need immediate local assessment. Food-access, medication, hormone, diet, equipment, and communication decisions need direct review with qualified clinicians and the person.