Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is the most recognised form of inherited childhood obesity.

Epidemiology

• Incidence: 1 in 10 000-15 000
• All ethnic groups
• Male = Female

Clinical Presentation

Clinical features are variable

• Breech presentation in utero
• Feeding problems in infancy
• Failure to thrive initially
• Hyperphagia
• Truncal obesity
• Morbid obesity developing between ages 1-6 years

Physical Signs

• Almond-shaped palpebral fissures
• Down-turned corners of the mouth
• Small hands and feet
• Hypotonia
• Microcephaly
• Hypogonadotrophic hypogonadism (males and females)
• Mental disability (IQ evenly distributed around 60 mark).
• Short  stature
• Dental malocclusion (40%)
• Cryptorchidism (80%)
• Labial hypoplasia
• Micropenis
• Strabismus (40-95%)

Complications

• Fertility is rare in men and un-common in women.
• Day time sleepiness is common (50-90%)
• Respiratory problems and sleep apnoea requiring anaesthetic precautions
• Congestive heart failure due to morbid obesity
• Diabetes mellitus (15%)
• Older children and adults are often depressed