II. Epidemiology
- Incidence: 1 in 16,000 births
- Most common form of Genetic Syndrome related Obesity
III. Pathophysiology
- Associated with defect on long arm of Chromosome 15
IV. Signs
- Newborn
- Hypotonia
- Poor sucking reflex
- Diminished cry
- Somnolence
- Infant
- Feeding difficulties and Failure to Thrive
- Increased eating starts after 1 year
- Early childhood (ages 1 to 6)
- Hyperphagia
- Rapid weight gain
- Classic dysmorphic facial features
- Narrow face at temples
- Almond shaped eyes
- Mouth corners turn downward
- Narrow Nasal Bridge
- Strabismus
- Thin upper lip
- Other features
- Morbid Obesity (onset after 12 months)
- Developmental Delay and learning disabilities
- Short Stature
- Hypogonadism (e.g. Cryptorchidism, small Testes)
- Skin Hypopigmentation
V. Labs: Genetic Testing
- Indications: All suspected cases of Prader-Willi
- Test Sensitivity: 100%
- Tests (both are done)
- High resolution karyotype
- Methylation analysis (specific for PWS)
VI. Associated conditions
VII. Management
-
Consultations
- Ophthalmology for Strabismus and Myopia
- Pediatric endocrinology for possible Growth Hormone
- Developmental pediatrician
- Speech therapy
- Physical therapy and occupational therapy
- Conditions to observe for and manage
- Failure to Thrive as infant
- Hypoventilation
- Respiratory infections
- Preventive strategies
- Closely supervise dietary intake
- Daily Physical Activity
VIII. Resources
- Prader-Willi Syndrome Association