Print Friendly - Prader-Willi Syndrome

My mum has a friend whose baby girl was born with Prader-Willi Syndrome. I had never heard about it. Since then I have seen a BBC documentary on the subject but it only covered the condition in adolescence. It may be that this article may be of no use to anyone but if it helps raise awareness and makes people more accepting it will have done its job.

People with PWS have a flaw in the part of their brain (the hypothalamus) that determines hunger and satiety (fullness). These people never feel full enough, so they have a continuous urge to eat. To compound this problem, people with PWS need considerably fewer calories than normal to maintain an appropriate weight. The obesity that results is the major cause of illness and death in this disorder. As in the general population, obesity in PWS can cause high blood pressure, respiratory difficulties, diabetes as well as other problems.

Prader-Willi Syndrome (PWS) is caused by a chromosomal abnormality which occurs around the time of conception. It is usually (in around 70% of cases) caused by the deletion of chromosome 15 inherited by the father, occasionally (about 25% of the time) it is caused by inheriting two chromosome 15’s from the mother. It can also, rarely, be caused by an irregularity on chromosome 15. However no blame is attached to either parent as PWS is thought to be a purely accidental occurrence. It is uncertain of the incidence rate of PWS but it is thought to be between 1 in 10,000 and 1 in 25,000.

Babies born with PWS are floppy and have low muscle tone which leads to a weak or absent ability to suck. They often have smaller hands and feet and undeveloped genitalia. They often reach developmental milestones such as sitting, crawling, standing and walking later but usually reach them all by the age of 5. Infants with PWS are very lovable and placid, and seem to draw admiration wherever they go.

Between the ages of 1 and 4, usually as the child becomes more mobile, the second stage of PWS occurs. The child starts to develop a heightened interest in food and although the degree of this varies greatly between individuals, there is always a preoccupation with food in talk and play. In severe cases the child develops an insatiable appetite and will try and get food by any means possible, including stealing. Some parents have to put locks of kitchen doors and cupboards to stop their children gorging on food. If it is not carefully managed, weight gain can be rapid so good dietary control is essential. If weight is not controlled, fat accumulates in a characteristic way on the buttocks, stomach, lower trunk and thighs. Children with PWS are on the whole very placid and loving but can be prone to aggressive or stubborn behavior if denied access to food.

Unfortunately people with PWS often never reach full sexual maturity and there are only 3 logged cases worldwide of women with PWS having children. As adults sufferers of PWS vary in there ability to carry out a ‘normal’ life, although all need some support to control their eating and therefore their weight. Most people with PWS have learning difficulties, the average IQ for a PWS sufferer is around 70. Despite the fact that many people with PWS have the abilities required to hold down a job, most are not emotional or socially developed enough to cope with the stresses of work. Many, however, get involved in voluntary work and make a very positive contribution to society in that way. Most sufferers live with there families but many more now are starting to live in residential homes or supported in the community. In the past life expectancy was short because of the health problems related to obesity but with greater understanding and dietary controls, many people are starting to live longer: the oldest known woman living in the UK is 72!

Unfortunately there is no "cure" for PWS. There have been many advances in the fields of genetics, but it will be several years before the genes which are involved in PWS are fully identified. No drug so far has proved to be of lasting help with regard to suppressing appetite. Generally speaking however, many of the adverse effects of the syndrome can be lessened by good dietary management, exercise programmes, good general health care, and by good general management of behaviour and education. The help of a dietitian, paediatrician, physiotherapist, educational psychologist, and (if necessary) speech therapist should be sought as soon as a diagnosis is made.