PWS is a genetic disorder, which means that it is passed on from parents to children. It is present from birth, although a diagnosis is typically not made until later in life. People with PWS may have difficulties eating due to intense hunger pangs (cravings) that can never be satisfied. They may also have problems maintaining body temperature during cold spells or when they first get out of bed in the morning. Other common symptoms include weak muscles, low bone density, and sleep disorders.
The severity of each person's symptoms will vary. Some people with PWS may only have occasional trouble eating enough food, while others may require daily nutritional support to stay healthy. There is no cure for PWS, but there are many treatments available that may help reduce some of the symptoms.
People with PWS are at risk for several health problems. Their appetite may decline over time, which can lead to weight loss. Also, since they cannot maintain normal body temperature, they are at risk for developing hypothermia. Because of this, it is important that people with PWS avoid exposure to cold temperatures.
Additionally, people with PWS are at risk for obesity-related diseases such as type 2 diabetes and heart disease. These risks can be reduced through regular exercise and maintenance of a healthy weight.
Prader-Willi syndrome (PWS) is a hereditary condition caused by the inactivation of several genes on chromosome 15. Symptoms in infants include weak muscles, poor eating, and sluggish growth. Those affected develop an insatiable hunger as children, which commonly leads to obesity and type 2 diabetes. People with PWS are at increased risk of developing schizophrenia and other mental illnesses.
The two main genes responsible for PWS have been identified; one produces a protein called CITOR1, while the other makes a protein called MECP2. Both of these genes must be inactive for signs of the disease to appear. Individuals who are only carriers of the gene but do not show any symptoms themselves may pass the gene on to their children. Carriers of the defective gene can be identified using a test called a methylation assay. This test looks at how much of an enzyme's activity has been inhibited by comparing it to controls. If the enzyme activity is less than expected, this indicates that the person is carrying the PWS gene and likely to produce an infant with the disorder.
People with one active copy of each of these genes typically do not display any signs or symptoms of PWS. They are also not at risk of passing the disease on to their children.
In individuals with two inactive copies of both genes, signs of the disorder will appear soon after birth. These signs include low muscle tone, difficulty feeding, and slow growth.
Prader-Willi syndrome (PWS) is a hereditary condition that affects around one in every 15,000 births. PWS affects both men and women equally, and it affects people of all colors and ethnicities. PWS is the most frequent genetic cause of life-threatening juvenile obesity. People with PWS are at increased risk for developing cardiovascular disease, diabetes, and other health problems associated with obesity.
People with PWS are more likely to be obese as children and adults. About 85% of individuals with PWS are overweight or obese. Obesity is the leading cause of death in individuals with PWS; other common causes of death include respiratory illness and suicide.
Individuals with PWS are also at risk for several other conditions related to obesity. They are likely to have high levels of cholesterol and triglycerides, which can lead to heart disease. Their blood pressure may be higher than normal, which increases their risk for having a stroke or other cardiovascular event. The pain receptors in their feet may not work properly, so they may have difficulty feeling how steep the stairs are or any changes in their foot temperature. Going without eating or drinking during periods of emotional stress may seem like a good idea but can lead to serious medical complications including dehydration, acidosis, and starvation wounds.
The severity of symptoms in individuals with PWS varies greatly.
A clinician will generally make a suspected diagnosis of Prader-Willi syndrome (PWS) based on clinical findings. Any infant born with substantial hypotonia should be suspected of having PWS (muscle weakness or "floppiness"). A blood test confirms the diagnosis. Genetic testing is also available to confirm the diagnosis by looking for mutations in the paternal copy of the SNRPN gene. This can be done either from a blood sample or from frozen tissue samples.
The diagnostic criteria for PWS are listed below. These criteria must all be satisfied for a diagnosis of PWS to be made. It is not enough that some of these features are present; all must be satisfied.
Hypogonadism - Low testosterone levels. Most males with PWS have low levels of testosterone when they are adults. Some may have normal levels as children but then begin to decline at about age 10. The cause of this hypogonadism has not been determined. Low testosterone may lead to increased fat storage in the body, particularly around the belly and thighs.
Cerebral dysfunction - Symptoms include mental retardation, learning problems, poor coordination, vision problems, epilepsy, and many more. As many as one in four people with PWS will develop dementia before they die. The type of dementia that person will experience is related to which part of the brain is affected first by the disease process.
Prader-Willi syndrome (PWS) and Down syndrome (DS) are two distinct chromosomal abnormalities with certain clinical symptoms in common, such as obesity, muscle hypotonia, ligament laxity, and mental retardation. PWS is a complicated multisystemic condition that affects both men and women equally. It is caused by the absence or severe reduction of expression of genes on chromosome 15, primarily from maternal transmission. The severity of physical features and cognitive abilities varies among individuals with PWS. Compared to people with DS, those with PWS tend to be shorter and stockier. Also, compared to people without the syndrome, those with PWS have greater difficulty maintaining body temperature in cold weather and experiencing hunger. They are at risk for developing cardiovascular disease and diabetes later in life.
People with PWS often exhibit hyperphagia-or an increased appetite-which can lead to morbid obesity. They also often experience frequent mood swings ranging from elation to despair. Cognitively, people with PWS perform within the normal range of intelligence but may show specific problems with tasks that require visual perception or memory. Many aspects of behavior associated with addiction disorders are present in people with PWS including craving, dependence, withdrawal, and relapse.
Unlike people with DS who generally have a full complement of 46 chromosomes, people with PWS usually only have one copy of each chromosome derived from their mother or father.