Prader-Willi syndrome ( PWS ) is a genetic disorder due to loss of certain gene functions. In newborns symptoms include weak muscles, poor eating, and slow development. Early childhood people become constantly hungry which often leads to obesity and type 2 diabetes. There are also mild and moderate intellectual disabilities and behavioral problems. Often narrow forehead, small hands and feet, short height, light-colored skin, and those affected can not have children.
Approximately 74% of cases occur when part of the father's chromosome 15 is removed. In another 25% of cases the person has two copies of chromosome 15 from their mother and none of their fathers. When the chromosome part of the mother is turned off, the edges do not have a copy of a particular gene. PWS is generally not inherited but genetic alteration occurs during the formation of eggs, sperm, or in early development. No known risk factors. Those with one child with PWS had less than 1% of the likelihood of the next child affected. A similar mechanism occurs in Angelman's syndrome unless there is a defective chromosome 15 from the mother or two copies of the father.
Prader-Willi syndrome has no cure. Treatment, however, can improve results, especially if done early on. In newborns, difficulty eating can be supported with a food tube. Strict food control is usually required starting around the age of three combined with an exercise program. Growth hormone therapy also improves results. Counseling and medication can help with some behavioral problems. Group homes are often needed in adulthood.
PWS affects between 1 in 10,000 and 30,000 people. Men and women are affected equally. This condition was named after Andrea Prader, Heinrich Willi, and Alexis Labhart who described it in detail in 1956. The previous description occurred in 1887 by John Langdon Down.
Video Prader-Willi syndrome
Signs and symptoms
There are many signs and symptoms of Prader-Willi syndrome. Symptoms can range from poor muscle tone during infancy to behavior problems in early childhood. Some of the symptoms that are usually found in infants, in addition to poor muscle tone, will be a lack of eye coordination; some are born with almond-shaped eyes; and because of poor muscle tone, the baby may not have strong sucking reflexes. Their cries are weak, and they have difficulty getting up. Another sign of this condition is the thin upper lip.
The more visible aspects of clinical features include hypotonia and abnormal neurological function, hypogonadism, developmental and cognitive delays, hyperphagia and obesity, short stature, and behavioral and psychiatric disorders.
Holm et al. (1993) describes the following features and signs as a pretest indicator of PWS, although not all will be present.
Womb and birth
Childhood
Adulthood
Physical appearance
Neuro-cognitive
Individuals with PWS risk learning difficulties and attention. Curfs and Fryns (1992) investigated the different levels of learning disabilities found in PWS. Their results, using IQ sizes, are as follows:
- 5%: IQ above 85 (high to low low intelligence)
- 27%: IQ 70-85 (limit of intellectual function)
- 39%: IQ 50-70 (mild intellectual disability)
- 27%: IQ 35-50 (moderate intellectual disability)
- 1%: IQ 20-35 (severe intellectual disability)
- & lt; 1%: IQ & lt; 20 (deep intellectual disability)
Cassidy found that 40% of individuals with PWS had an average/low intelligence limit, a figure higher than 32% found in the Curfs and Fryns study. However, both studies show that most individuals (50-65%) are included in the mild/low/low light intelligence range.
Children with PWS show an unusual cognitive profile. They are often strong in organization and visual perception, including reading and vocabulary, but their spoken language (sometimes influenced by hypernasality) is generally poorer than their understanding. The skill marked in solving jigsaw puzzles has been noted, but this may be the effect of increased exercise.
The processing of auditory information and sequential processing is relatively poor, as are the arithmetic and writing abilities, short-term visual and auditory memory and auditory attention spans. This sometimes improves with age, but deficits in these areas remain throughout adulthood.
There may be a connection with psychosis.
Behavior
Prader-Willi syndrome is often associated with a constant, extreme, and greedy appetite, which persists no matter how much a patient eats, often resulting in unhealthy obesity. Caregivers should really limit the patient's access to food, usually by installing a lock on the refrigerator and in all the cupboards and cupboards where food is stored. This is the most common genetic cause of morbid obesity in children. There is currently no consensus on the cause of this symptom, although genetic abnormalities on chromosome 15 disrupt the normal functioning of the hypothalamus. Given that the core of the arcuate hypothalamus governs many basic processes, including appetite, there may be relationships. In the hypothalamus of people with PWS, nerve cells that produce oxytocin, a hormone that is thought to contribute to satiety, have been found to be abnormal.
People with Prader-Willi syndrome have high levels of ghrelin, which are thought to contribute directly to the increase in appetite, hyperphagia, and obesity seen in this syndrome. Cassidy expressed the need for clear delineation of behavioral expectations, strengthening behavioral limits and establishing routine routines.
The major mental health difficulties experienced by people with PWS include compulsive behavior (usually manifested in skin picking) and anxiety. Psychiatric symptoms, for example, hallucinations, paranoia and depression, have been described in some cases and affect about 5-10% of young adults. Patients are also often very stubborn and irritable. Psychological problems and behavior are the most common causes of hospitalization.
It is typical for 70-90% of affected individuals to develop behavioral patterns in early childhood. Aspects of these patterns can include stubbornness, anger, control and manipulative behavior, difficulties with changes in routine, and compulsive behavior.
Endocrine
There are several aspects of PWS that support the concept of growth hormone deficiency in individuals with PWS. In particular, individuals with short stature PWS, obese with abnormal body composition, have reduced fat-free mass (FFM), have reduced lean body mass (LBM) and total energy expenditure, and decreased bone density.
PWS is characterized by hypogonadism. It is manifested as a non-descending testicle in men and early benign adrenarche in women. The testes can go down with time or can be managed by surgery or replacement of testosterone. Adrenarke can be treated with hormone replacement therapy.
Ophthalmologic
PWS is commonly associated with the development of strabismus. In one study, more than 50% of patients had strabismus, especially esotropia.
Maps Prader-Willi syndrome
Genetics
PWS is a disorder caused by an epigenetic phenomenon known as imprinting. PWS is caused by the removal of a paternal copy of the SNRPN and the necdin gene along with the snoRNA group: SNORD64, SNORD107, SNORD108 and two copies of SNORD109, 29 copies of SNORD116 (HBII-85) and 48 copies SNORD115 (HBII- 85) 52). This is on chromosome 15 located in the region of 15q11-13. This PWS/AS region may be lost by one of several genetic mechanisms that, in most instances, occur through accidental mutations. Other less common mechanisms include; uniparental disomy, sporadic mutation, chromosomal translocation, and gene deletion. Because of imprinting, the copy of the maternally inherited gene is almost silent, only a copy of the gene from the expressed paternal. PWS results from the loss of paternal copies of this region. Removal of the same region on the maternal chromosome causes Angelman (US) syndrome. PWS and AS are the first examples of human recording disorders.
The risk for siblings of an affected child having PWS depends on the genetic mechanisms that cause the disorder. The risk for siblings is & lt; 1% if the affected child has gene removal or uniparental disomy, up to 50% if the affected child has a mutation from the imprinting control area, and up to 25% if parental chromosome translocation is present. Prenatal examination is possible for all known genetic mechanisms.
A microbial in a family of HBII-52 snoRNAs has extracted it from playing a major role in the disease.
The study of human and mouse model systems has demonstrated the deletion of 29 copies of the box SND/SN0116 (HBII-85) to be a major cause of Prader-Willi syndrome.
Diagnosis
It is traditionally characterized by hypotonia, short stature, hyperphagia, obesity, behavioral problems (particularly OCD-like behavior), small hands and feet, hypogonadism, and mild intellectual disabilities. However, with early diagnosis and early treatment (such as with growth hormone therapy), the prognosis for people with PWS begins to change. Like autism, PWS is a spectrum disorder and symptoms can range from mild to severe and may change throughout a person's lifetime. Various organ systems are affected.
Traditionally, Prader-Willi syndrome is diagnosed with a clinical presentation. Currently, the syndrome is diagnosed by genetic testing; testing is recommended for newborns with pronounced hypotonia. The initial diagnosis of PWS allows for early intervention as well as early growth hormone prescription. Daily recombinant growth hormone injections (GH) are indicated for children with PWS. GH supports linear growth and increased muscle mass, and can reduce food preoccupation and weight gain.
The mainstay of diagnosis is genetic testing, specifically DNA-based methylation testing to detect the absence of Prader-Willi/Angelman syndrome (PWS/AS) syndrome contribution on chromosome 15q11-q13. Such tests detect more than 97% of cases. Special methylation tests are important to confirm the diagnosis of PWS in all individuals, but especially those who are too young to demonstrate features sufficient to make clinical-based diagnoses or in individuals with atypical findings.
Prader-Willi syndrome is often misdiagnosed as another syndrome due to much of the medical community's unfamiliarity with PWS. Sometimes misdiagnosed as Down syndrome, simply because of the relative frequency of Down syndrome compared to PWS.
Treatment
Prader-Willi syndrome has no cure; However, some treatments are done to reduce symptoms of the condition. During infancy, subjects should undergo therapy to increase muscle strength. Speech and occupational therapy are also indicated. During the school years, children benefit from a highly structured learning environment and extra help. The biggest problem associated with this syndrome is severe obesity. Access to food should be closely watched and limited, typically by installing keys in all food storage areas including refrigerators.
Because hypotonia can be a symptom of PWS, it is important to provide proper nutrition during infancy. It is also very important to emphasize physical activity in individuals with PWS for all ages to optimize strength and promote a healthy lifestyle.
Prescriptions of daily recombinant growth hormone injections are indicated for children with PWS. GH supports linear growth and increased muscle mass, and can reduce food preoccupation and weight gain.
Due to severe obesity, obstructive sleep apnea is a common sequel, and positive air pressure machines are often needed. There may be times when someone who has been diagnosed with PWS may have to undergo a surgical procedure. One operation that proved unsuccessful to treat obesity was a gastric bypass. Patients with Prader-Willi syndrome have a very high tolerance for pain; therefore they may experience significant stomach symptoms such as acute gastritis, appendicitis, or cholecystitis and do not realize it until later.
Behavioral and psychiatric issues must be detected early on for best results. These problems are best when handled with parental education and training. Sometimes drugs are also introduced. Serotonin agonists are most effective in reducing anger and compulsive enhancement.
Epidemiology
PWS affects approximately 1 in 10,000 to 1 in 25,000 newborns. There are over 400,000 people living with PWS around the world.
Society and culture
Despite its scarcity, Prader-Willi syndrome has often been referenced in popular culture, partly out of curiosity around the insatiable appetite and the overweight that is symptomatic.
Prader-Willi syndrome has been described and documented several times on television. A fictitious individual with Prader-Willi syndrome is featured in the episode "Dog Eat Dog" from the CSI television series Crime Scene Investigation, which aired on November 24, 2005. In the English media in July 2007, Channel 4 aired a 2006 documentary entitled Can not Stop Eating , circulates the daily lives of two people with Prader-Willi syndrome, Joe and Tamara. In the episode of May 9, 2010 Sheryl Crow helps Ty Pennington rebuild a home for a family whose youngest son, Ethan Starkweather, lives with Prader-Willi syndrome. In the episode of March 22, 2012 Mystery Diagnosis in the Discovery Health channel, Conor Heybach, who has Prader-Willi syndrome, shares his story of how he was diagnosed with it.
See also
- Genomic Printing
- Epigenetic
- ROHHAD
References
External links
- Prader-Willi syndrome in Curlie (based on DMOZ)
Source of the article : Wikipedia
0 Comments