What is Prader-Willi syndrome?
Prader-Willi syndrome is a rare and complex genetic condition resulting from a defect or changes to chromosome 15 that usually affects intellect, behavior, appearance, growth, and development.
What causes Prader-Willi syndrome?
Experts aren’t sure exactly why some children are born with defects or other abnormalities to chromosome 15 which result in Prader-Willi Syndrome. It seems to happen by chance and is not passed down in families. Around one in 10,000 to 30,000 children are born with the syndrome.
Defects on chromosome 15 affect the hypothalamus, which is the part of the brain that regulates hormones, appetite, the development of muscle tone and the expression of emotions.
About 70% of cases of Prader-Willi syndrome occur when a segment of the chromosome 15 inherited from the father is deleted in each cell. In another 25 percent of cases, two copies of chromosome 15 are inherited from the mother instead of one copy from each parent. Rarely, Prader-Willi syndrome can be caused by a chromosomal rearrangement or other defects.
What are the symptoms of Prader-Willi syndrome?
Symptoms start from birth and progress as the child gets older.
Symptoms during infancy include:
- Weak muscle tone (hypotonia) or “floppiness”
- Feeding difficulties and trouble sucking
- Poor growth
- Delayed development.
As the child gets older, they develop an insatiable appetite, which leads to chronic overeating and obesity; many also develop type 2 diabetes as a result.
Compared to children and adults their age, people with Prader-Willi Syndrome are shorter than usual, with small hands and feet, and distinctive facial features, such as a narrow forehead, almond-shaped eyes, and a triangular mouth. Some have unusually fair skin and light-colored hair
People with Prader-Willi syndrome have mild-to-moderate intellectual impairment and learning disabilities. Behavioral problems, such as temper tantrums and stubbornness, and compulsive behavior, such as picking at the skin, are common.
Many have sleep or breathing difficulties and both males and females have underdeveloped genitals. Puberty is delayed or incomplete, and most are infertile.
How is Prader-Willi syndrome diagnosed?
If you suspect your child has Prader-Willi Syndrome, see your doctor. Genetic testing can determine if they have the condition or not.
How is Prader-Willi syndrome treated?
Although there is no cure for Prader-Willi Syndrome, treatment can help reduce the effects of complications of the disorder such as type 2 diabetes and obesity. Treatments may include:
- Strict dietary supervision
- Exercise to build muscle mass
- Behavioral management
- Growth hormone treatment may be considered in some children.
Children and people with Prader-Willi Syndrome also benefit from ongoing support from health professionals.