What is Prader-Willi Syndrome?
What is Prader-Willi Syndrome?
Prader-Willi syndrome (PWS) is the most common known genetic cause of life-threatening obesity in children. Although the cause is complex it results from an abnormality on the 15th chromosome that affects the hypothalamus in the brain which regulates many of the bodies systems. It occurs in males and females equally and in all races. Prevalence is 1: 12,000 to 1: 15,000.
Most Common Characteristics?
At birth, the infant typically has low birth weight for gestation, hypotonia (weak muscles), and difficulty sucking which can lead to a diagnosis of failure to thrive. The second stage “thriving too well”, has a typical onset between the ages of two and five, but can be later. The hyperphagia (extreme unsatisfied drive to consume food) lasts throughout the lifetime. That, coupled with a metabolism that utilizes drastically fewer calories than normal, can lead to excessive eating and life-threatening obesity. The food compulsion makes constant supervision necessary.
Children with PWS have sweet and loving personalities, but typically also have some behavior problems, motor development delays, and unique medical issues such as high pain threshold, dysfunction of regulation of temperature, and lack of vomiting which can all mask a life-threatening condition. They also have short stature and low muscle tone if not treated with growth hormone, incomplete sexual development, and a chronic feeling of hunger. Average IQ is 70, but even those with normal IQs almost all have learning issues.
How is Prader-Willi Diagnosed?
Individuals who have clinical findings should be referred for genetic testing. DNA methylation analysis confirms the diagnosis of PWS. Any infant who has hypotonia with poor suck and no other obvious diagnosis should be tested for PWS. Recurrence risk is only in very rare cases with imprinting mutations, translocations, or inversions.
To date, no medication or surgical intervention has been found that would eliminate the need for strict dieting and supervision around food. Growth hormone treatment, because it increases muscle mass and function, may allow a higher daily calorie level. It is the only FDA approved drug for PWS. Psychotropic medications can be helpful if there is a good understanding of what works with the syndrome. Most effective is early diagnosis and early education of parents on management. Early diagnosis saves lives
About the Prader-Willi Syndrome Association (USA)
Prader-Willi Syndrome Association (USA) is the only national membership organization dedicated to serving individuals affected by Prader-Willi syndrome, their families, and interested professionals. Research, extensive educational materials, crisis counselors, a New Parent Mentoring program, conferences, email support groups, and other services provided. For more information, call 1-800-926-4797 or go to www.pwsausa.org.
About Author Janalee Heinemann, MSW – parent of an adult son with PWS; masters in social work from Washington University in St Louis, MO; volunteer for PWSA (USA) for 16 years prior to becoming Executive Director from 1997 — 2007. Currently Director of Research & Medical Affairs for PWSA (USA). Prader-Willi Syndrome Association (USA) www.pwsausa.org