PRADER WILLI SYNDROME

What is Prader Willi Syndrome?

Prader-Willi syndrome (PWS) is a genetic disorder that occurs in approximately one out of every 15,000 births. PWS affects males and females with equal frequency and affects all races and ethnicities. PWS is recognized as the most common genetic cause of life-threatening childhood obesity.

 

PWS was first described by Swiss doctors Andrea Prader, Alexis Labhart, and Heinrich Willi in 1956 based on the clinical characteristics of nine children they examined. 

Causes of Prader Willi Syndrome:

PWS is the result of an abnormality on chromosome 15. There are three ways that this can happen:

• First, if there is a deletion of critical genes on a portion of the 15th chromosome. This happen in most cases.

• Second, the entire chromosome from father is missing and there are instead, two chromosomes from the mother. This condition is known as uniparental disomy.

• Third, there is an imprinting mutation on chromosome 15 contributed by the father. This condition can be seen in a very small percentage of cases i.e, 3%. 

Symptoms of Prader Willi Syndrome:

The symptoms of PWS change over time in individuals. Overall, there are two general stages of the symptoms associated with PWS:

Early stage:

•Infants with PWS are hypotonic or “floppy”, with very low muscle tone due to poor arousal, poor interest in eating, decreased swallowing, and failure to thrive.

•A weak cry and a poor suck reflex. 

•Motor milestones are achieved, but are usually delayed.

•Toddlers typically enter a period where they may begin to gain weight easily, prior to having a heightened interest in food. In simple words, they are hungry all the times leading to gain weight.

Childhood or beyond stage:

•An unregulated appetite and easy weight gain characterize the later stages of PWS. Most probably between 3 and 8 years old.

•Individuals with PWS lack normal hunger and satiety cues. They usually are not able to control their food intake and will overeat if not closely monitored.  In addition, the metabolic rate of persons with PWS is lower than normal. 

•Individuals usually exhibit cognitive challenges, with measured IQs ranging from low, normal to moderate intellectual disability. 

•Other issues may include growth hormone deficiency, small hands and feet, scoliosis (an abnormal curvature of the spine), sleep disturbances with excessive daytime sleepiness, high pain threshold, speech apraxia (the complete loss of this ability) /dyspraxia (the partial loss of the ability to co-ordinate and perform skilled), and infertility. 

•Obsessive-compulsive symptoms, skin picking, and difficulty controlling emotions.

 

•Adults with PWS are at increased risk for mental illness. 

Diet for Prader Willi Syndrome:

Individuals with Prader-Willi syndrome (PWS) will face evolving nutritional issues throughout their lives. It is important to ensure adequate dietary habits for brain growth and development while preventing excessive weight gain. Hence following are the dietary habits that should be provided to PWS individuals throughout their life cycles: 

1. Newborn period:

As PWS babies have poor suck reflex, so they are usually fed with special soft nipples or nasogastric or gastrostomy tube feedings until they are 6 months old. They also may need frequent weight checks at medical appointments. 

2. Infancy to preschool period:

An insatiable appetite may be seen as early as 12 months old. When children develop insatiable appetites, food intake must be controlled. Usually, a very rapid weight gain occurs, even with low-calorie diets. Caloric diets (>800 kcal/day) should be adjusted to maintain appropriate weight for height. Rapid weight gain can lead to life-threatening obesity. 

So, PWS individuals must follow a balance diet with vitamins and minerals supplementation. To monitor growth and acceleration, including weight and height PWS specific standardized growth charts should be use.

3. School age period: 

In addition to weight control, behavioral and social challenges occur as children enter school. Uncontrolled eating leading to morbid obesity may be controlled by following ways:

•Lock up food (refrigerator, cupboards, or pantries).

•Provide lunches from home (sack lunch or lunch box) since school lunches will be too high in calories.

•Communicate with the school and childcare personnel about diet restrictions. 

•Develop physical activity plans for the family and with the school to help maintain the child's weight and increase the child's muscle tone.

•Provide vitamin and calcium supplements to prevent vitamin deficiencies and osteoporosis.

•Restrict fluid intake to prevent fluid overload.

4. Adolescence period:

Adolescence is a time of body changes and awareness of differences between individuals. There is a strong need for the child to maintain a reasonable weight. Food sharing and activities where food is present will increase the frustration of being on a controlled diet and stealing food may increase.

•Caloric restrictions need to be adjusted for the individual's height from 1,000 to 1,200 kcal/day.

•Adequate calcium and multivitamins must be given.

•Exercise programs, at least 30 minutes in length, should be a part of everyday activities.

•One-on-one supervision may be needed when in the cafeteria.

5. Adult period:

Adults with PWS do not live on their own; they may be living in group homes. They may begin to use public transportation, and this will offer opportunities for them to buy or steal food. New supervisors may need to be educated about monitoring and controlling dietary intake.

Calories will remain between 1,000-1,200 kcal/day. Some diets may include 600-800 kcal per day if rapid weight loss is needed. The lower calorie diet may be dependent on physical activity level and the amount of weight gain. 

A goal for body mass index (BMI) might be to maintain at <30 for adults depending on the status of the individual with PWS. Calcium and multivitamin supplements must be given to prevent further osteoporosis. Frequent weight checks are necessary during this new time of independence and change of supervision.

PWS is just a genetic disorder and individual with PWS need care and support as there is unfortunately no treatment or cure of this syndrome. Hence, lets spread awareness about PWS. 

Musharrafa Asad

References:

https://www.fpwr.org/about-prader-willi-syndrome#causes

https://www.webmd.com/parenting/baby/prader-willi-syndrome#1

https://www.pwsausa.org/what-is-prader-willi-syndrome/

https://www.pws.org.nz/about-pws/stages-of-pws