What is Prader-Willi syndrome?

Causes and Symptoms

Prader-Willi syndrome is caused by a spontaneous deletion involving chromosome 15. Although this disease is genetic in nature, most parents of children with Prader-Willi syndrome have normal chromosomes. Some research indicates an association between the disease and fathers employed at the time of conception in fields associated with hydrocarbons, such as lumbermen, chemists, or mechanics. That connection might implicate an environmental trigger in some cases.

Prader-Willi syndrome occurs in one in 12,000–15,000 births and affects both genders and all races. Newborns with the disease appear floppy, with low muscle tone. They often had a low birth weight, and males may have undescended testicles. Small genitalia are common, as are small hands and feet. These babies feed poorly and display poor motor development. Mental retardation is common, ranging from mild to severe.

Between the ages of two and four, children with Prader-Willi syndrome develop an insatiable need to eat. They will do anything to get food and will eat without control. Obesity and other related health problems are major concerns for these patients. Many patients also suffer from behavioral disorders related to excessive eating, compulsive or repetitive behaviors, tantrums, and psychiatric disorders including depression and, in extreme cases, psychoses.

Treatment and Therapy

Primary treatment for Prader-Willi syndrome centers on the many health concerns related to obesity, in addition to meeting the educational, social, and emotional needs of patients as they grow and mature. Studies indicate an abnormally high level of the hormone ghrelin in these patients. It is the only appetite-stimulating hormone produced in the stomach and was touted in the early twenty-first century as a possible breakthrough in treatment.

Dietary restrictions, including types of food and portion control, are critical with these patients. Since they are unable to control their cravings for food, cooperation among family, school personnel, and community members is essential. Regular exercise is also recommended. Because patients with Prader-Willi syndrome are often small in stature, growth
hormones are often used to facilitate growth and decrease the percentage of body fat, thus helping improve both strength and agility in patients. Special education services, including speech, behavioral assistance, and psychological or psychiatric services, are also important components of treatment.

Perspective and Prospects

Prader-Willi syndrome was first defined as a syndrome by Andrea Prader, Alexis Labhart, and Heinrich Willi in 1956. Prader and Willi refined the syndrome in 1963. Since the mid-twentieth century, researchers have focused on the influences of hormones and genetics in the development and treatment of this disease. Treatments evolved based on increased knowledge of how genes and hormones influence human biology and behavior.

Bibliography

American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders: DSM-5. 5th ed. Washington, D.C.: American Psychiatric Association, 2013.

Cassidy, Susanne B. “Prader-Willi Syndrome.” Journal of Medical Genetics 34 (1997): 917–923.

Jones, Kenneth Lyons. “Prader-Willi Syndrome.” In Smith’s Recognizable Patterns of Human Malformation. 6th ed. Philadelphia: Saunders/Elsevier, 2006.

MedlinePlus. "Prader-Willi Syndrome." MedlinePlus, May 13, 2013.

Prader-Willi Syndrome Association USA.Prader-Willi Syndrome Association USA, n.d.

Sadock, Benjamin J., and Virginia A. Sadock. Kaplan and Sadock’s Concise Textbook of Clinical Psychiatry. 3d ed. Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins, 2009.