Question: What are the symptoms of Prader-Willi syndrome ?
Answer: What are the signs and symptoms of Prader-Willi syndrome? In infancy, Prader-Willi syndrome (PWS) is characterized by weak muscle tone (hypotonia), feeding difficulties, poor growth, and delayed development. In later infancy or early childhood, affected children develop an extreme appetite, which leads to overeating and obesity. Other signs and symptoms of PWS may include: mild to moderate intellectual disability sleep abnormalities unusually fair skin underdeveloped genitals delayed or incomplete puberty short stature strabismus scoliosis small hands and feet distinctive facial features such as a narrow forehead, almond-shaped eyes, and a triangular mouth Behavioral problems are common and often include temper tantrums, stubbornness, and obsessive-compulsive tendencies. The Human Phenotype Ontology provides the following list of signs and symptoms for Prader-Willi syndrome. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Delayed speech and language development 90% Failure to thrive in infancy 90% Generalized hypotonia 90% Growth hormone deficiency 90% Hypogonadotrophic hypogonadism 90% Infertility 90% Motor delay 90% Narrow palm 90% Obesity 90% Polyphagia 90% Poor suck 90% Short foot 90% Short palm 90% Short stature 90% Specific learning disability 90% Cryptorchidism 85% Attention deficit hyperactivity disorder 75% Scrotal hypoplasia 69% Adrenal insufficiency 60% Primary amenorrhea 56% Abnormality of chromosome segregation 50% Abnormality of dental enamel 50% Abnormality of the palate 50% Almond-shaped palpebral fissure 50% Behavioral abnormality 50% Brachydactyly syndrome 50% Clinodactyly of the 5th finger 50% Clitoral hypoplasia 50% Cognitive impairment 50% Cutaneous photosensitivity 50% Decreased muscle mass 50% Delayed puberty 50% Delayed skeletal maturation 50% Downturned corners of mouth 50% Glomerulopathy 50% Hypoplasia of penis 50% Hypoplasia of the ear cartilage 50% Hypoplastic labia minora 50% Incoordination 50% Intrauterine growth retardation 50% Kyphosis 50% Microcephaly 50% Micropenis 50% Muscular hypotonia 50% Narrow forehead 50% Narrow nasal bridge 50% Nasal speech 50% Recurrent respiratory infections 50% Scoliosis 50% Seizures 50% Single transverse palmar crease 50% Sleep apnea 50% Strabismus 50% Telecanthus 50% Type I diabetes mellitus 50% Hypopigmentation of hair 33% Hypopigmentation of the skin 33% Impaired pain sensation 33% Iris hypopigmentation 33% Oligomenorrhea 33% Ventriculomegaly 33% Type II diabetes mellitus 25% Autism 19% Psychosis 15% Hip dysplasia 10% Carious teeth 7.5% Esotropia 7.5% Frontal upsweep of hair 7.5% Myopia 7.5% Osteopenia 7.5% Osteoporosis 7.5% Poor fine motor coordination 7.5% Radial deviation of finger 7.5% Syndactyly 7.5% Temperature instability 7.5% Upslanted palpebral fissure 7.5% Precocious puberty 4% Abdominal obesity - Clinodactyly - Decreased fetal movement - Dolichocephaly - Generalized hypopigmentation - Hyperinsulinemia - Hypermetropia - Hypoventilation - Poor gross motor coordination - Sporadic - The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.
Source: GARD

Question: What causes Prader-Willi syndrome ?
Answer: What causes Prader-Willi syndrome? Prader-Willi syndrome (PWS) is caused by the loss of active genes in a specific region of chromosome 15. People normally inherit one copy of chromosome 15 from each parent. Some genes on chromosome 15 are only active (or "expressed") on the copy that is inherited from a person's father (the paternal copy). When genes are only active if inherited from a specific parent, it is called genomic imprinting. About 70% of cases of PWS occur when a person is missing specific genes on the long arm of the paternal copy of chromosome 15. This is called a deletion. While there are copies of these same genes on the maternal copy of chromosome 15, the maternal copies of these genes are not expressed. In about 25% of cases, PWS is due to a person inheriting only 2 maternal copies of chromosome 15, instead of one copy from each parent. This is called maternal uniparental disomy. Rarely (in about 2% of cases), PWS is caused by a rearrangement of chromosome material called a translocation, or by a change (mutation) or other defect that abnormally inactivates genes on the paternal chromosome 15. Each of these genetic changes result in a loss of gene function on part of chromosome 15, likely causing the characteristic features of PWS.
Source: GARD

Question: Is Prader-Willi syndrome inherited ?
Answer: Is Prader-Willi syndrome inherited? Most cases of Prader-Willi syndrome (PWS) are not inherited and are due to random events during the formation of egg or sperm cells, or in early fetal development. This is usually the case when PWS is caused by a deletion in the paternal chromosome 15, or by maternal uniparental disomy. However in rare cases, a genetic change responsible for PWS can be inherited. The risk to family members of a person with PWS depends on the genetic cause of the condition in the affected person. Because the various genetic causes of PWS are complex, people seeking information about specific risks to themselves or family members are encouraged to speak with a genetics professional. More information about the causes of PWS can be viewed on our Web site here.
Source: GARD

Question: How to diagnose Prader-Willi syndrome ?
Answer: How is Prader-Willi syndrome diagnosed? There are clinical diagnostic criteria for Prader-Willi syndrome (PWS) that were developed in the past that continue to be useful. These criteria can be viewed on the National Institute of Health's NICHD Web site. However, the current mainstay of a diagnosis when PWS is suspected is a form of genetic testing called DNA methylation testing. This testing can detect abnormal, parent-specific imprinting on the region of chromosome 15 that is responsible for PWS. It determines whether the region is maternally inherited only (i.e., the paternally contributed region is absent) and confirms a diagnosis in more than 99% of affected people. DNA methylation testing is especially important in people who have non-classic features, or are too young to show enough features to make the diagnosis based on signs and symptoms alone.
Source: GARD

Question: What are the treatments for Prader-Willi syndrome ?
Answer: How might Prader-Willi syndrome be treated? A multidisciplinary team approach is ideal for the treatment of people with Prader-Willi syndrome (PWS). Early diagnosis, early multidisciplinary care, and growth hormone treatment have greatly improved the quality of life of many affected children. In general, management of this condition depends on the affected person's age and symptoms. When a diagnosis of PWS is made, several evaluations are needed to assess the extent of the condition. For example, newborns should be assessed for sucking problems; infants should be assessed for development; and young children should have a vision exam. All males should be evaluated for the presence of cryptorchidism. Other associated conditions for which evaluations may be recommended include hypothyroidism, scoliosis, behavioral problems, psychosis, and respiratory problems and sleep issues. In infants, special feeding techniques may be needed. Young children often need early intervention, including physical therapy for muscle strength and reaching physical milestones, and speech therapy for language issues. Cryptorchidism may resolve on its own but usually requires hormonal and/or surgical treatment. When excessive eating begins and weight percentiles increase, affected children should be on a program of a well-balanced diet, exercise, and close supervision with food. A consultation with a dietitian is recommended. Behavioral problems may be addressed with special behavioral management programs. Serotonin uptake inhibitors have helped many affected teenagers and adults, particularly those with obsessive-compulsive symptoms. Growth hormone treatment can normalize height, increase lean body mass, increase mobility, and decrease fat mass. Controlled trials of growth hormone therapies have shown significant benefit from infancy through adulthood. Benefits may include an increase in language and cognitive skills, and better motor performance. Sex hormone replacement helps to produce secondary sex characteristics (those that develop during puberty) but is somewhat controversial due to possible behavior problems in males, risk of stroke, and hygiene concerns related to menstruation in females. Clinical trials investigating potential treatment options for people with PWS are ongoing. ClinicalTrials.gov provides patients, family members, and members of the public with current information on clinical research studies. People interested in participating in clinical trials are encouraged to visit this site to determine if any trials would be helpful. Use each study's contact information to learn more. You can view a list of clinical trials for PWS here. To learn more about how to find and participate in a research study, clinical trial, or patient registry, view our Get Involved in Research page. Additional information on this topic can be found at the links below. Foundation for Prader-Willi Research - Diagnosis & Treatment GeneReviews - Prader-Willi Syndrome Medscape - Prader-Willi Syndrome
Source: GARD