Prader-Willi syndrome (PWS) is a genetic condition that affects a person’s appetite, growth, metabolism, development, intellect and behavior. Signs and symptoms of PWS are present shortly after birth and can include low muscle tone (hypotonia), trouble feeding, and slow growth. Children and adults with PWS do not feel full and will always feel hungry, which leads to overeating. The excessive eating, along with a slow metabolism, typically causes a person with PWS to be overweight (obese). PWS also causes specific facial features, including a narrow forehead, almond shaped eyes, and a triangular mouth. Short stature, developmental delays, trouble sleeping, and stubborn behavior are also features of PWS. Most people with PWS cannot have children (are infertile) due to incomplete sexual development (puberty).
PWS occurs when a person does not have a full copy of chromosome 15 that came from their mother and a full copy that came from their father. The most common genetic cause is a missing (deleted) piece of chromosome 15. Some cases are a result of having two chromosome 15 copies that came from the mother and none that came from the father (uniparental disomy). Most cases occur randomly and are not inherited from a parent. PWS affects both males and females.
PWS is typically suspected in babies who have trouble gaining weight and have low muscle tone or in children, teenagers, and adults who eat too much and have learning problems. The diagnosis can only be confirmed through a genetic blood test. Early diagnosis will allow for early intervention and support. To help decrease the chance for obesity, constant monitoring of a child’s food intake is needed. Locking the cabinets and refrigerator is usually necessary. If your child has been diagnosed with PWS, talk to their doctor about the most current treatment options. Support groups can connect you with other families affected by PWS.