What are the key clinical features to consider when diagnosing Prader-Willi Syndrome in a child?

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Posted: 22 August 2025Updated: 22 August 2025 Guideline-Aligned (High Confidence) Clinically Reviewed
Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX

Key clinical features to consider when diagnosing Prader-Willi Syndrome (PWS) in a child include:

  • Neonatal hypotonia and feeding difficulties: Infants typically present with marked hypotonia leading to poor suck and failure to thrive in early infancy .
  • Developmental delay and intellectual disability: Mild to moderate cognitive impairment and delayed motor milestones are common .
  • Characteristic facial features: These include a narrow forehead, almond-shaped eyes, and a thin upper lip .
  • Hyperphagia and obesity: From early childhood, an insatiable appetite develops, often leading to severe obesity if uncontrolled .
  • Endocrine abnormalities: Hypogonadism with genital hypoplasia, growth hormone deficiency, and short stature are typical .
  • Behavioral and psychiatric features: Temper tantrums, obsessive-compulsive behaviors, and sleep disturbances are frequently observed .
  • Sleep disorders: Excessive daytime sleepiness and sleep apnea are common and contribute to morbidity .

These features together form the clinical basis for suspecting PWS, which should prompt genetic testing for confirmation .

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