DEFINITION
Prader-Willi syndrome (PWS) is a rare and complex genetic disorder that alters appetite, development, metabolism as well as intellectual behavior and function. This disease is characterized by small stature, behavioral problems, defective sexual development, low muscle tone and an uncontrolled appetite that leads to life threatening obesity. Those suffering from PWS needs help and rigid external controls, sometimes including restricting access to food as there is a constant chronic feeling of insatiable hunger which when not properly managed can develop to morbid obesity leading to life-threatening heart and lung complications, diabetes, high blood pressure and some other serious complications . An important feature of Prader-Willi syndrome is a constant sense of hunger that usually begins at about 2 years of age.
CAUSES
Genes always come in pair with one originating from the mother (Maternal gene) and the other originating from the father (Paternal gene). PWS is as a result of the deficiency of the paternal gene in chromosome 15 (one of the 23 pairs of chromosomes in humans). In major cases, a defect occurs, the essential and critical paternal genes are missing and in other cases the entire paternal gene is missing leaving the presence of two chromosome 15 from the mother. This defect on chromosome 15 leads to a disintegration in the regular function of a part of the brain referred to as the hypothalamus. The hypothalamus influences the release of hormones. Since there is a problem with the proper functioning of the hypothalamus, processes such as hunger, growth, sexual development can be interfered with.
SIGNS AND SYMPTOMS
Signs and symptom may vary from person to person. It can start from infancy and extend to early childhood and then adulthood.
INFANCY – Signs and symptoms include:
Poor muscle tone which can make a baby to feel limp when held
Underdeveloped genital
Different facial feature like an almond shaped eys
Poor sucking response
EARLY CHILDHOOD – ADULTHOOD
Underdeveloped sex organs
Intellectual disability such as issues with thinking and reasoning
Poor growth and physical development
Excessive food craving
Weight gain
Speech problem
Behavioral problem
Sleeping disorder
Delayed motor development: Toddler suffering from PWS often start to walk and sleep later than most children do.
DIAGNOSIS AND TREATMENT
DIAGNOSIS
99% cases of PWS are diagnosed using the DNA methylation study. This study allows to check the PWS critical region of the chromosome 15. If the methylation study shows that the pattern is coherent with the maternal gene, this suggests that the paternal gene originating from the father is either not present or inactive. If the methylation shows PWS, additional test are carried out to determine the underlying cause of the disorder. This is essential in determining an increased risk in other family members having disorder.
TREATMENT
The treatment of PWS are directed to the specific symptoms that are present in each individual. The coordinated efforts of several specialist might be required in treating such cases. Clinical geneticists, pediatricians, orthopedists, endocrinologists, speech therapists, psychologists, dieticians, nutritionists, and other healthcare professionals may need to orderly plan an effectual program for the child’s treatment.
Gavage feeding might be used in infants to ensure adequate feeding. In this procedure a small, tube is passed to the stomach to help feed newborn baby with feeding disability.
Individual suffering from PWS may also benefit from the growth hormone therapy (GHT) which can help to reduce risk associated with PWS and help increase the quality of life. Studies has shown that GHT can improve behavior and growth. In June of 2000, the Food and Drug Administration (FDA) approved the use of human growth hormone for the treatment of children with genetically-confirmed PWS and evidence of growth failure. Studies have shown that starting the GH therapy as early as two to three months of age is more beneficial. This therapy has shown to improve facial figure and overall body build.