What is Prader-Willi Syndrome?
Understanding PWS
Prader-Willi Syndrome (PWS) is a neurogenetic disease caused by loss of function of genes of paternal origin in segment 15q11-q13.
It is a rare syndrome affecting 1 in 15,000 to 30,000 births. It is considered the main cause of obesity of genetic origin.
How does it occur?
About 70% of cases occur when a segment of paternal chromosome 15 is deleted in each cell.
Some genes are only activated in the paternal copy. This activation is due to genomic imprinting.
Symptoms in Intrauterine Life and Early Life
Still in intrauterine life, individuals with PWS present decreased movements.
With poor sucking, babies prefer to sleep most of the time due to hypotonia.
Main Characteristics
Development
- •Delay in neuromotor development
- •Difficulty in word articulation
- •Learning problems
Feeding
- •Constant feeling of hunger
- •Compulsive interest in food (hyperphagia)
- •Obesity
Physical
- •Short stature
- •Small hands and feet
- •Skin lighter than parents
- •Small mouth with thin upper lip
Others
- •Inactivity
- •Decreased pain sensitivity
- •Possible strabismus
Phases of the Syndrome
Phase 1 - Early Life
Characterized by growth deficit due to neonatal hypotonia.
Phase 2 - Transition
Weight gain precedes hyperphagia.
Phase 3 - Hyperphagia (from ~8 years)
Development of insatiable appetite, accompanied by aggressiveness in food seeking.
Recent studies show that PWS is a multi-stage syndrome.
Treatment
Interventions are extremely important to avoid obesity and associated health problems.
Treatment with growth hormone (GH) is the most effective therapy.