Symptoms of Prader Willi Syndrome

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Overview of Prader Willi Syndrome

Prader Willi syndrome is a medical condition brought about by a genetic problem in a region of chromosome 15. Normally, an invidiual will receive two active copies of this chromosome, one from each parent.

The problem with Prader Willi syndrome is that the chromosome 15 from the father appears to be inactive, which may be due to missing, or defective genes. Another way for the patient to acquire the condition is by inheriting no chromosome 15 from the father and instead, two chromosomes 15 come from the mother. Consequently the function of the hypothalamus, the part of the brain responsible for regulating thirst and hunger, is affected as is the release of hormones needed for sexual development and growth.


Generally, two stages of Prader Willi syndrome symptoms exist, namely stage 1 and stage 2. Stage 1 symptoms occur in newborns, where the infant exhibits floppy muscle tone which causes poor sucking reflexes. The inability of the infant to properly suck affects infant feeding and nutrition so gaining weight may become a problem thus compromising growth. Stage 2 symptoms occur when the child is between 1 to 6 years old where hypothalamic impairment is very much evident. The child has underdeveloped sexual organs, and is constantly hungry with no feeling of fullness. This can result in rapid weight gain and may in time cause the child to become obese.

Other Prader Willi syndrome symptoms exhibited by the patient include visual problems like nearsightedness and strabismus, physical and mental retardation, problems in speech and in sleeping, as well as postural defects such as scoliosis. Prader Willi syndrome affected children have distinctive physical features which include eyes shaped like almonds, down-turned mouth with thin lips especially on the upper part, narrow temples and a narrow nasal bridge.


The risk of patients developing complications related to obesity is high, especially if nothing is done to control the compulsive eating behavior. Prader Willi syndrome affected children may live to develop cardiovascular diseases, hypertension, inflamed joints, and type 2 diabetes. Sleep apnea may also occur which is characterized by interruptions in breathing due to periodic pauses.

Additionally, underdeveloped sexual organs may lead to a deficiency in the secretion of essential hormones, such as testosterone, progesterone and estrogen, which can eventually lead to osteoporosis and sterility.


There is no known available cure for children affected with Prader Willi syndrome. The management of patients with this condition is usually based on their symptoms. What is essential however is the maintenance of proper nutrition by ensuring a healthy diet, weight management to prevent further complications, and the adherence to an exercise program to help burn off the calories. Hormonal treatments using growth hormone and sex hormones are also being used in the management of these patients.

References Prader Willi Syndrome

University of Michigan Health System: Prader-Willi Syndrome (PWS)

MedlinePlus: Prader-Willi syndrome