Physical features

People with PWS often have distinguished facial and physical features that set them apart from other people; these include:

• Almond-shaped eyes
• Small hands and feet
• A downturned mouth
• A triangular-shaped upper lip
• A smaller, narrower forehead

Movement and coordination

People with Prader-Willi syndrome often have problems with mobility and coordination due to a lack of muscle tone; common symptoms include:

• Lack of muscle strength (especially in the larger muscle groups)
• Lack of balance
• Lack of coordination

Learning and development

Most people with PWS have a lower IQ than other people and subsequently suffer from learning difficulties; the average IQ for a person with PWS is 70, while the national average is 100. Common symptoms include:

• Problems with abstract concepts
• Problems with maths and numerical exercises
• Good at reading and writing
• Good at individual activities including word searches, jigsaw puzzles and drawing
• Slower growth
• Slower emotional development

Developmental stages

• Babies and small children

Babies with PWS are often floppy because they have very little muscle tone; they may also have difficulty suckling because of their weak muscles and many have to be tube fed for the first couple of days of their lives. Most children show very minor interest in feeding throughout the first couple of months and babies with PWs tend to sleep a lot and have a weaker cry than other babies.

Developmental milestones, including sitting independently, crawling, talking and walking usually come later in children with PWS; most children have mastered these skills by the age of 5.

• Primary school years

Many children start to develop an interest in eating and food during their childhood years and some may gain weight as a result; children’s diets should be well managed and controlled in order to satisfy them without encouraging them to put on weight.

Children tend to be very good-natured but they can become frustrated easily and may have outbursts of anger, especially if they are denied food.

• Adolescence

Puberty occurs much later in those with PWS and the sexual organs do not develop fully in most cases; there are only three reported cases of women with PWS having children across the world. Both men and women tend to be under-developed in terms of their sexual organs and characteristics.

People with PWS are often quite a lot shorter than the average height; there is no growth spurt during the teenage years and men reach an average height of 5’2, while women tend to get to around 4’10.

In some cases, behavioural problems can arise during the adolescent years and there may be problems which arise from the relationship between the individual and food.

• Adulthood

Some people are much more independent than others; however, all patients with PWs will require some degree of help and support. Many people have the intelligence to work but don’t have the social skills and the emotional strength to make it through the working day; many people with PWS turn their hand to volunteer work or creative activities instead.

Life expectancy has increased significantly in recent years and the oldest person living with PWS in the United Kingdom has reached the age of 72. Serious health problems, including strokes and heart disease are no more common amongst elder people with PWs than other people; however, mental health struggles may be more prevalent amongst those with Prader-Willi syndrome.

Prader-Willi syndrome

• Prader-Willi syndrome
• What are the causes of Prader-Willi syndrome?
• What are the symptoms of PWS?

• Physical features
• Treating PWS