Prader Willi syndrome

Prader-Willi syndrome is a congenital (present from birth) disease characterized by decrease in muscle tone, decreased mental capacity, hypogonadism and obesity.

Prader-Willi is caused by the deletion of a gene on chromosome 15. However, the reason for this is still unknown. Only the father's copy of the gene on chromosome 15 is active. The gene from the maternal side is inactive. The disease occurs, when the only copy received from father's side is deleted; since the maternal copy is always inactive.

At birth, new infants born with the disease are often very floppy (hypotonic) and small. Testicles in male infants may be undescended. The child shows slow mental and motor development, characteristically small hands and feet and increasing obesity.

The patient develops uncontrollable hunger, which becomes a cause for rapid weight gain. The weight gain leads to Obesity, respiratory failure with hypoxia and corpulmonale (right-sided heart failure). There is slow mental development, and the IQ seldom exceeds 80.

There is no general consensus as to the cause for morbid obesity, although genetic abnormalities in chromosome 15 obstructs the normal functioning of the hypothalamus. Since appetite and many other basic processes is regulated by hypothalamus, the resulting insatiable appetite maybe because of the failure. But the post-mortem investigation doesn't reveal any organic defect.

High ghrelin levels in Prader–Willi syndrome patients have direct contirbution in the increased appetite, obesity, and hyperphagia seen in this syndrome.

The mental health difficulties experienced by them include anxiety and compulsive behaviour. Approximately 5 - 10% of young adults have showcased psychiatric symptoms, like hallucinations, paranoia and depression. The most common cause of hospitalization are behavioural and psychiatric problems.

Symptoms/ Warning Signs
# Floppy new born infant (hypotonic)
# Slow mental development
# Delayed motor development
# Very small hands and feet
# Insatiable appetite
# Undescended testicles in the male infant
# Narrow skull
# Almond shaped eyes
# Rapid weight gain with marked obesity