PRADER WILLI SYNDROME

Esther OgbuAndrea Johnson

Tina Glendadakis

WHAT IS PRADER WILLI SYNDROME? Prader–Willi syndrome (PWS) is a

rare genetic disorder in which seven genes on chromosome 15 are deleted or unexpressed on the paternal chromosome.

It was first described in 1956 by Andrea Prader, Heinrich Willi, Alexis Labhart, Andrew Ziegler, and Guido Fanconi of Switzerland

CHARACTERISTICS

Symptoms are believed to be caused by dysfunction of a portion of the brain called the hypothalamus.

The hypothalamus is a small endocrine organ at the base of the brain that plays a crucial role in many bodily functions like, hunger and satiety, temperature and pain regulation, fluid balance, puberty, emotions, and fertility.

Although hypothalamic dysfunction is believed to lead to the symptoms of PWS, it is unclear how the genetic abnormality causes hypothalamic dysfunction.

There are two generally recognized stages of the symptoms associated with PWS

WWW.FPWR.ORG/ABOUT-PRADER-WILLI-SYNDROME

Stage 1In the first stage, infants with PWS are hypotonic or "floppy", with very low muscle tone. Weak cry and a poor suck reflex are typical. Babies with PWS usually are unable to breastfeed and frequently require tube feeding. These infants may suffer from "failure to thrive" if feeding difficulties are not carefully monitored and treated. As these children grow older, strength and muscle tone generally improve. Motor milestones are achieved, but are usually delayed.

Stage 2 An unregulated appetite

characterizes the second stage of PWS.

This stage most commonly begins between ages 2 and 6 years old.

Individuals with PWS lack normal hunger and satiety cues.

They usually are not able to control their food intake and will overeat if not closely monitored.

Food seeking behaviors are very common.

In addition, the metabolic rate of persons with PWS is lower than normal.

Left untreated, the combination of these problems will lead to morbid obesity and its many complications.

OTHER CHARACTER ISTICS

o Prader-Willi syndrome is considered a spectrum disorder, meaning not all symptoms will occur in everyone affected and the symptoms may range from mild to severe.

o People with Prader-Willi often have some mental strengths as well, such as skills in jigsaw puzzles. 

o If obesity is prevented, people with the syndrome can live a normal lifespan.

o Behavioral problems, usually during transitions and unanticipated changes, such as stubbornness or temper tantrums

o Delayed motor skills and speech due to low muscle tone

o Cognitive problems, ranging from near normal intelligence to mild mental retardation; learning disabilities are common

o Repetitive thoughts and verbalizations

o Collecting and hoarding of possessions

o Picking at skino Low sex hormone levels

FISH (fluorescence in situ hybridization)

A cytogenetic technique used to detect and localize the presence or absence of specific DNA sequences on chromosomes.

FISH uses fluorescent probes that bind to only those parts of the chromosome with which they show a high degree of sequence similarity.

Fluorescence microscopy can be used to find out where the fluorescent probe bound to the chromosomes.

FISH is often used for finding specific features in DNA for use in genetic counseling, medicine, and species identification.

FISH can also be used to detect and localize specific mRNAs within tissue samples.

In this context, it can help define the spatial-temporal patterns of gene expression within cells and tissues.

Diagnoses of Prader Willi

Methylation of mammalian DNA has long been recognized to play a major role in different cellular functions as development or control of gene expression and is generally associated with transcriptional repression.

MethylCollector™ Ultrafast magnetic assay for specific isolation of CpG-methylated DNA MethylCollector™ Ultra offers a fast magnetic assay capable of efficiently isolating methylated CpG islands from fragmented genomic DNA*.

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Genetic Testing

TREATMENT In multiple studies, human growth hormone (HGH) has been found to be beneficial in treating Prader-Willi syndrome.

In June of 2000, HGH was officially recognized by the Federal Drug Administration (FDA) in the United States and other countries for use in patients with Prader-Willi syndrome.

HGH is effective not only in increasing height, but also Decreasing body fat, increasing muscle mass Improving weight distribution Increasing stamina, Increasing bone mineral density

Despite this, many difficult symptoms associated with PWS remain untreated. To date, no effective medications have been found to regulate appetite. Inability to control food intake is often the biggest obstacle keeping those with PWS from living independently. In addition, medical treatment of the psychiatric and behavioral issues associated with PWS has produced inconsistent results.

OTHER TREATMENTS

Exercise and physical activity can help control weight and help with motor skills. 

Speech therapy may be needed to help with oral skills.

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