What is prader willi syndrome?
Prader-Willi's syndrome was described for the first time in 1956 by the Swiss doctors Andrea Prader, Alexis Labhart and Heinrich Willi. In 1961, a second publication of Prader and Willi. They noticed that the combination of muscle weakness, uncontrollable appetite and some physical characteristics could not be accidental. Today, we know that the syndrome is the result of a genetic defect. The cause is the lack of a small piece of genetic information on chromosome 15. In the Netherlands, every year about 10 children born with Prader Willi syndrome. It is equally common in boys than in girls. Incidentally, John Langdon Down in 1887 described a girl with striking features that fit the Prader Willi syndrome.
Feature
in infants
-Low birth weight and poor weight gain.
-(Often severe), muscle weakness (hypotonia).
-Few spontaneous movements.
-Little and softly cry and sleep a lot.
-Power Problems (the baby has a poor sucking reflex which it drinks little and very slowly).
-Some physical characteristics such as: a narrow forehead, a narrow nose, almond-shaped eyes, a thin triangular shaped upper lip, girls underdeveloped labia and boys too small penis and often non-undescended balls
In toddlers, preschoolers and school children
-Sharp change in diet, whereby there is not only an increase in appetite, but also the tendency to eat abnormal things, such as chalk or soap.
-Relatively low energy requirements of the body.
-Common (severe) obesity.
-Lag in the development of motor skills.
-(Mild to moderate) disadvantage in intellectual development.
-Usually an easy, accommodating character, but with occasional big tantrums.
-Decreased sensitivity to pain.
-Less fever infections.
-Many scratching and picking at wounds.
-Small hands and feet.
In adolescents and adults
-Learning difficulties persist; Most adults have a mild to moderate intellectual disability.
-Sexual development is not only or late. Mainly in men is rare sexual activity. Most men with Prader Willi syndrome are infertile. Woman can be fruitful, especially if they are not overweight.
-The body length in males with an average of 1.55 m; in women 1.50 m.
Strong, sometimes insatiable appetite, which can lead to vastly overweight (obese).
-Periods of daytime sleepiness (need for "naps").
-Usually a calm, quiet and friendly character, with periods of severe tantrums and stubbornness.
-In adults, mental health problems can occur, such as sudden violent outbursts and periods of depressed or psychotic behavior.
Development
Nutrition and Weight
Children with Prader-Willi drink very difficult. In the first months often require tube feeding. After six months of drinking is usually better. From the age of about one year, children can develop an almost insatiable appetite. Moreover, the normal amount of food per day is too much for them. The energy of their body is about 30 percent below average. Without early diagnosis, these children are therefore very fast too thick.
Motor development
The child usually has a severe congenital muscular weakness (hypotonia). It moves and cries little weak. All of Infancy much can be done with physical therapy to improve control of muscle tone (head balance, trunk balance). Usually the child is not very mobile; the motor milestones are reached later than usual. It is let down (around 12 months) and run (around 30 months). Sometimes there are problems with balance. It also happens that the motor development is almost normal.
Speech Development
The speech-language development is usually slow, and the speech is often hyper-nasal. Muscle weakness in the mouth area can affect the good unfolding of the speech. Speech therapy at a young age is not only useful to stimulate the child suck, but also for the further speech and language development.
Intellectual development
The intellectual development is usually delayed. Many children with the syndrome to special education (ML or ZML). Sometimes they can respect their intellectual functioning actually attend primary school but they come by their childish behavior in compression between the other students. Most adult people with the syndrome have mild to moderate intellectual disability. There are also some people who are normally gifted and in a few cases, there is a severe intellectual disability. After secondary (special) education and sometimes some adults can get by quite independent individual vocational training. However, it is difficult to control eating behavior can be a bummer. Many adults therefore continue to rely on guidance to live and work. The average IQ is 70, with a wide variety upwards and downwards. Individuals with Prader Willi syndrome often function below their level (especially learning disability); abstract thinking and mathematics are difficult for them. People with Prader Willi syndrome have many things need more time than others (low treatment rate).
Behavior
Young children with the syndrome usually make a warm and happy impression. Later, especially in puberty can get showers of moodiness, irritability and stubbornness. For educators, it is not easy to find a balance between encouraging the strengths of the child and the other to protect against disappointments that are almost inevitable due to the disability. The strong desire to eat a eetdwang actually, besides providing the mood swings often the most problems.
Health
When the weight can be kept under control, the life expectancy of people with the Prader-Willi syndrome basically normal. As a result of being overweight can joint problems (back, ankles) and diabetes (diabetes mellitus) arose.
Prader willi syndrome cause
Prader Willi syndrome is caused by the absence of a piece of information that is normally present in the chromosome number 15. The absence of that piece of information may have originated in three different ways.
Deletion
In 70 percent of cases of Prader Willi syndrome is caused by deletion. It is missing a piece from one of the two chromosomes number 15. More precisely, missing a number of genes (a small piece of DNA) from the long arm of the chromosome 15 (15q11-13). The special feature here is that the chromosome 15, which is missing a piece of DNA, always coming Father's. The absence of the piece of DNA from chromosome 15 usually occurs by accident during the formation of sperm. The chances of that happening is very small, because the "wrong" is not already present in either parent. The recurrence risk in a subsequent pregnancy is therefore extremely small.
Uniparental maternal disomy
In about 28 percent of cases there is a uniparental disomy. Here there is no piece of DNA is missing from one of the two chromosomes # 15, but turn out to both number 15 chromosomes derived from the mother. Normally, the 23 pairs of chromosomes in each body cell from each pair comes from the mother and one from the father. When in the egg of the mother "accidentally" two number 15 chromosomes are present and in the sperm of the father just like normal one is present, there is a fertilized egg with three chromosome number 15. Then there is one chromosome number 15 too much present, after which one of the three must disappear. Now number 15 chromosome from the father disappears, there remain two identical chromosomes number 15 of the mother and apparently lacking the necessary paternal information. This is why uniparental (= one parent) disomy (= two chromosomes) called. The emergence of a fertilized egg with three chromosome number 15 is extremely small. The risk of recurrence in a subsequent pregnancy is therefore also very small.
Aflees Disorder (inprentingsstoornis)
In 2 to 5 percent of the cases it is a imprintingsstoornis. When the father-derived chromosome number 15 is present, but the details of that part of a chromosome for whatever reason, can not be read, it is as if that information is missing. The genesis of the Prader-Willi by mistracking is rare. The risk of recurrence in this case is, however, still exists, since the presence of reading errors or can be passed on.
Prenatal testing is possible
For the determination with certainty of the diagnosis of Prader Willi syndrome examination of the chromosomes is therefore of great importance. If the proper cause is found, can be performed during another pregnancy DNA research in the fruit (chorionic villus sampling or amniocentesis).
Chromosome 15
Another syndrome where the 'mistake' is also located on chromosome 15, has Angelman syndrome. In this syndrome is the chromosome 15 that the piece of DNA mist always supplied by the mother, as opposed to the Prader Willi syndrome wherein said missing piece is always derived from the father. There is also a partial tetrasomie 15. In addition to the 46 chromosomes that normally occur in every cell of the body they have a small (part of a) extra chromosome that is originated from chromosome 15.
Medical Information
Prader Willi syndrome in most doctors' offices or only very rarely. Maybe this will be desired about the knowledge often. Below are problems occurring in the syndrome, mentioned that could cause some medical complications.
Central adrenal insufficiency
Recently, a group of Dutch researchers demonstrated that a part of the children with Prader Willi syndrome has central adrenal insufficiency during stress. This means that during periods of intense psychological stress, illness, surgery, accident, etc. lacking the function of the adrenal gland. The adrenal cortisol. A lack of cortisol can have serious consequences at the time of illness. This condition is to be treated with drugs, which can be given during stress situations. This can be discussed with the attending pediatrician.
Sleep / breathing disorders
Because sometimes it can be a huge obesity hypoventilation syndrome (disorder of breathing), and apnea (cessation of breathing) occur during sleep. This occurs especially in very obese people with Prader Willi syndrome, sometimes with normal weight. Losing weight can reduce the problem. Excessive daytime sleepiness (excessive daytime sleepiness) is a common symptom. Children can fall asleep in class, especially in the afternoon.
Enhanced response to some drugs
Especially with drugs for weight loss and behavior modification. Intramuscular administration may cause prolonged sedative effect of the drug.
High pain threshold and impaired temperature regulation
Both may mask an infection. Individuals with Prader Willi syndrome will often complain of pain until the infection is severe. Often they have no or low fever infection or illness.
Potential problems with anesthesia
Problems related to hypotonia (careful with muscle relaxants), impaired thermoregulation (leading to hyper and sometimes hypothermia or overheating or hypothermia of the body), cardiovascular disorders (such as hypertension, arrhythmias), obese (intubation) and related diabetes Mellitus (Type 2) from teen age, and tendency to convulsions (muscle twitches) (avoiding epileptogenic anesthetics preference: halothane). In the anesthesia, account should be taken of the possible existence of central adrenal insufficiency during stress.
Inability to vomit
People with Prader-Willi vomiting very rarely, even though they eat inedible things like waste. If anyone still go broke then you should be aware that something serious is going on. There is an increased risk of diarrhea.
Crabs and fleece
Excoriation disorder is a common problem. People with Prader Willi syndrome have scars and wounds in various stages of healing. The wounds are often months held open by pick. Due to the higher threshold of pain experienced by people with the Prader Willi syndrome, the risk of damage is greater. Prevention is better than cure.
Hypotonia
Infants often have a poor sucking reflex and also later in life poor muscle tone. The speech and language development may be delayed.
Some common medical aspects
-Scoliosis (rugverkromming) is common, often unrecognized.
-Diabetes mellitus (type II): mainly depends on weight.
-Caries: not good close to each of teeth; thick, smelly saliva; poor oral hygiene.
-Myopia (nearsightedness); strabismus (crossed eyes) very frequently.
-Inguinal hernia (hernia) and / or cryptorchidism (not descend from the testes).
-Hypogonadism (underdeveloped sexual organs).
-Individuals with the Prader Willi syndrome are usually sterile and have a limited length growth.
Prader willi syndrome treatment
Because the Prader Willi syndrome is caused by a defect in the DNA, the syndrome is not curable. Or to combat some symptoms. In view of the extensive and very different symptomology of patients with Prader Willi syndrome, there are several treatment options. The main treatments are growth hormone treatment and possibly treatment (gluco) corticosteroids for adrenal insufficiency. Information about adrenal fatigue is shown above and can be found on the website of the Foundation for Child and Growth. In addition there are specific treatments, such as hormonal or surgical treatment of undescended testes (cryptorchidism), hormonal therapy for an absent or delayed pubertal development, and masking the good eye by a patch to squint (strabismus).