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PRADER-WILLI SYNDROME

Mental Health, Psychological Disorders / By

PRADER-WILLI SYNDROME

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 Prader-Willi syndrome 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 a pair
  • One originating from the mother (Maternal gene) and the other originating from the father (Paternal gene).
  • Prader-Willi syndrome occurs as a result of lack 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.
  • In other cases, the entire paternal gene is missing leaving the presence of two genes 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 feel limp when held

Underdeveloped genital

A different facial feature like an almond-shaped eyes

Poor sucking response

EARLY CHILDHOOD – ADULTHOOD

Underdeveloped sex organs

An 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 Prader-Willi Syndrome are diagnosed using the DNA methylation study.
  • This study allows checking the 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, an additional test is carried out to determine the underlying cause of the disorder.
  • Fluorescent in situ hybridization (FISH)  test can also be used in diagnosing the syndrome. The test analysis chromosomes and can detect deletion. Deletion of the paternal gene is the most common cause of the Prader-Willi Syndrome.
TREATMENT
  • The treatment of PWS is directed to the specific symptoms that are present in each individual.
  • The coordinated efforts of several specialists 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, thin tube is passed through the nose and mouth to the stomach to help feed the newborn baby with feeding disability.
  • An 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 have shown that growth hormone therapy can improve behavior and growth. In June 2000, the Food and Drug Administration (FDA) approved the use of human growth hormone therapy for the treatment of children with genetically-confirmed PWS and evidence of growth failure. Studies have shown that starting the growth hormone 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.