© Getty Images

What is it? -

As mentioned, Prader-Willi Syndrome (PWS) is a rare genetic disorder that can manifest itself through a number of physical symptoms, learning difficulties, and behavioral problems.

© Shutterstock

What causes it? -

The condition is caused by the loss of function of some genetic material in a group of genes on chromosome number 15.

© Shutterstock

Is it hereditary? -

Generally, no. It’s mostly the result of random occurrences, but there are cases where PWS can reoccur within a family.

© Shutterstock

How it works -

PWS affects the hypothalamus, which is the part of the brain that controls functions such as hunger, emotions, pain, and body temperature.

© Shutterstock

How it is measured -

Like autism and ADHD, the syndrome has a spectrum and different people are affected to a different degree.

© Shutterstock

When was it discovered? -

The syndrome was first discovered in 1956 by Swiss doctors Andrea Prader, Alexis Labhart, and Heinrich Willi.

© Shutterstock

How many people does it affect? -

It is estimated that one in 10,000 to 30,000 people worldwide suffer from Prader-Willi syndrome.

© Shutterstock

Who does it affect? -

The syndrome affects both males and females and all races and ethnicities with equal frequency.

© Shutterstock

Physical features -

People who suffer from Prader-Willi Syndrome have distinctive physical features.

© Shutterstock

Early symptoms -

The first symptoms usually include decreased muscle tone (hypotonia) and delayed growth and development.

© Shutterstock

Early symptoms -

Babies who suffer from PWS also present feeding difficulties and are usually unable to breastfeed.

© Shutterstock

Main symptom -

As infants with PWS transition to childhood, an insatiable, uncontrollable appetite is one of the most common symptoms.

© Shutterstock

Appetite -

This chronic overeating (hyperphagia) can lead to obesity and consequently lead children to develop conditions such as type 2 diabetes.

© Getty Images

Obesity -

Hyperphagia can also contribute to respiratory difficulties and even heart failure, linked to obesity.

© Getty Images

Physical characteristics -

People with PWS are usually short in stature and have small hands and feet, with some also suffering from scoliosis.

© Getty Images

Physical characteristics -

Those with Prader-Willi syndrome can also have characteristic facial features, including a narrow forehead, almond-shaped eyes, and a triangular mouth.

© Getty Images

Physical characteristics -

Both male and female sufferers have underdeveloped g e n i t a l s, and most are infertile.

© Shutterstock

Symptoms -

Learning difficulties and behavioral problems are among the most common symptoms. These include temper outbursts and stubbornness.

© Shutterstock

Symptoms -

Another symptom is compulsive behavior. Skin picking, for instance, is common.

© Shutterstock

Symptoms -

PWS sufferers can also experience sleep disturbances. Daytime sleepiness is a common symptom.

© Shutterstock

Symptoms -

Difficulty controlling emotions has also been identified as a symptom in those suffering from PWS.

© Shutterstock

Mental health risk -

Adults with PWS are at a higher risk for mental illness.

© Shutterstock

How is PWS diagnosed? -

The syndrome is diagnosed through a blood test called a methylation analysis.

© Shutterstock

Is there a cure? -

There is no cure for PWS. There are, however, ways to manage some of the symptoms.

© Shutterstock

Treatment -

Managing weight and diet are of utmost importance, but so is the management of the mental symptoms.

© Shutterstock

Treatment -

Parents might need to seek help from dieticians, therapists, and other physicians.

© Shutterstock

Treatment -

Some children might require specific hormonal treatments to support muscle growth, such as growth hormone injections.

© Shutterstock

The future -

Organizations such as the Foundation for Prader-Willi Research are conducting studies and exploring alternatives such as genetic therapy.

Sources: (Foundation for Prader-Willi Research) (MedlinePlus) (NHS) (Prader-Willi Syndrome Association UK) 

See also: Celebs who kept their serious illnesses a secret

© Shutterstock