Prader Willi Syndrome

Prader Willi Syndrome causes a wide range of physical, mental and medical problems due to the deletion or absence of some genes in the long chain of chromosome 15. Children affected by this condition find it difficult to thrive as it results in poor growth, weak muscle tone and delayed growth and motor developments. Also, they are intellectually impaired and exhibit certain behavioral and speech problems. The syndrome often leads to obesity even at a very young age.

Sponsored link

Living with Prader Willi Syndrome is not easy especially since it is incurable. Even so, treatment can give the needed help for the affected persons to manage the symptoms and prevent complications from happening. The syndrome is usually treated under the close supervision of a team of health care professionals who will design the treatment plan based on the special dietary, medical and behavioral needs of the patient.


Prader Willi Syndrome (PWS) is brought forth by the absence or defects of some of the genes in chromosome 15. This genetic deletion causes the hallmark features of the syndrome. Experts had uncovered which genes are missing or defective in the case of PWS, and these are:

  • Small nucleolar RNAs

SnoRNAs are responsible in giving instructions for the production of molecules that will regulate other RNA molecules. The loss of SnoRNA genes causes the characteristic features of PWS.

  • OCA2

The OCA2 gene is involved in producing a certain type of protein that determines the pigmentation or coloring of eyes, skin and hair. The absence of the OCA2 gene in chromosome 15 results in the unusually light-colored hair and fair skin among PWS patients.

Genetic studies revealed that the paternal copy – or the genetic copy inherited from the father, is usually affected. PWS could arise due to:

  • Deletion of the paternal genetic material in chromosome 15

The missing genetic material in the paternal copy of chromosome 15 comprises around 70% of PWS cases. The deletion of some genes also turns the maternal copy of chromosome 15 inactive.

  • Paternal copy of chromosome 15 is completely absent

In around 25% to 30% of PWS cases, the paternal copy of chromosome 15 is completely absent. This means that the patient has two maternal copies of chromosome 15 instead of having one copy from each parent.

  • Genetic mutation or translocation

In rare cases, PWS is the result of a genetic mutation or chromosomal translocation which makes the genes of the paternal copy of chromosome 15 to become inactive.

Sponsored link


Studies have shown that people affected by PWS have a dysfunctional hypothalamus – the part of the brain that controls various bodily functions. How the chromosomal abnormality involving the paternal copy of chromosome 15 causes the hypothalamus to malfunction is still being investigated. One thing is sure though, a problematic hypothalamus affects hunger, temperature, emotions, pain regulation, fertility and many more.

Though the condition is already present at birth, the symptoms will likely be noticed within the first 12 months of the child’s life. Other identifying symptoms become more pronounced as the child grows older.

  • Distinctive facial features

Children with PWS have narrow foreheads, triangular mouths, almond-shaped eyes, thin upper lips and short stature. They have little hands and feet as well as unusually light-colored hair and fair skin.

  • Developmental delay

Infants born with PWS have incredibly low muscle tone making them appear floppy. They generally have a weak cry and unable to flex their knees and elbows. They are too small for their age and become somewhat malnourished due to feeding difficulties. Poor eye coordination, slow response to stimulation and unusual tiredness can also be observed.

  • Hormonal imbalance and food craving

Hormonal imbalance causes delayed puberty, underdeveloped genitals and infertility. In addition, Prader Willi syndrome is the leading cause of childhood obesity.  Furthermore, the afflicted children exhibit constant food cravings and even strange food-seeking behaviors.

  • Delayed motor skills

PWS also causes babies to sit and walk much later than their contemporaries. This is more pronounced during childhood up to adulthood when the patient is observed to be significantly much shorter compared to other members of the family.

  • Intellectual disability

Cognitive abilities could be slightly or moderately affected. Speech is also delayed and sufferers find it difficult to express themselves in speaking and writing.

Children affected by Prader Willi Syndrome also have behavioral problems, mental retardation, sleeping disorders as well as scoliosis. PWS rarely occurs, affecting 1 out of 10,000 to 30,000 live births, often as a result random events during conception.


Having a child with PWS can be overwhelming and put a family in an emotional and mental turmoil. Being aware of the root cause of the condition will help take away feelings of guilt and drive them to seek treatment and live with the disorder.

The treatment will address the problems associated with Prader Willi Syndrome, such as:

  • Poor growth
  • Low muscle tone
  • Obesity
  • Delayed physical and mental development
  • Speech and behavioral problems
Sponsored link

Be the first to comment

Leave a Reply

Your email address will not be published.