Prader-Willi Syndrome

What is Prader-Willi syndrome?

Prader-Willi syndrome is a rare genetic disorder that results in a number of physical, mental, and behavioral problems that all stem from a constant sense of hunger beginning at about two years of age. The obesity that results from this hyperphagia (never feeling full) and constant eating cause many other complications of the condition, intellectual impairment, and learning disabilities.

What causes Prader-Willi syndrome?

Prader-Willi syndrome is a genetic disorder, caused by an error in one or more genes located in a particular region of chromosome 15. Either paternal genes on chromosome 15 are missing, two copies of chromosome 15 were inherited from the mother and none from the father, or there’s some error in paternal genes on chromosome 15. Overall, these errors disrupt the normal functions of the hypothalamus, the part of the brain responsible for releasing hormones. In most cases, the error in chromosome 15 is not inherited, but rather caused by a spontaneous genetic error.

What are the symptoms of Prader-Willi syndrome?

Symptoms of Prader-Willi syndrome vary among individuals, but generally they slowly change over time from childhood to adulthood. Signs and symptoms present at birth include:

• Poor muscle tone
• Distinctive facial features
• Poor sucking reflex
• Generally poor responsiveness
• Underdeveloped genitals

From early childhood to adulthood, the signs and symptoms of Prader-Willi syndrome include:

• Food craving and weight gain
• Underdeveloped sex organs and poor growth and physical development
• Cognitive impairment and delayed motor impairment
• Speech problems
• Behavioral problems
• Sleep disorders

In addition to these, children with Prader-Willi syndrome generally have distinctive facial features such as a narrow forehead, almond-shaped eyes, a triangular mouth, short stature, and small hands and feet.

How is Prader-Willi syndrome diagnosed?

Usually, doctors will suspect Prader-Willi syndrome based on an observation of the characteristic signs and symptoms of the disorder. A blood test can be made after to look at the patient’s chromosomes and confirm a diagnosis. Early diagnosis can improve the quality of life for people with Prader-Willi syndrome

What are the available treatments for Prader-Willi syndrome?

Specific treatments will vary depending on each particular case of Prader-Willi syndrome, but generally, the follow therapies are needed:

• Good nutrition for infants
• Human growth hormone treatment to increase growth, improve muscle tone, and decrease body fat
• Sex hormone treatment
• Weight management
• Treatment of sleep disturbances
• Behavioral and physical therapy

Where can I find more information on Prader-Willi syndrome?

• Mayo Clinic
• NIH
• Prader-Willi Syndrome Association (USA)