Medically Reviewed on 3/2/2022
Children with Prader-Willi syndrome may have almond-shaped eyes, a narrow forehead, turned-down mouth, thin upper lip, and underdeveloped genitalia
Prader-Willi syndrome (PWS) can cause a wide range of symptoms that affect a child’s physical, psychological, and behavioral development. Children with Prader-Willi syndrome may have the following signs and symptoms:
- Almond-shaped eyes
- Narrow forehead
- Turned-down mouth
- Thin upper lip
- Underdeveloped genitalia
- Poor muscle tone, which may cause a weak sucking reflex
- Sleepiness and difficulty waking up
- Poor response to stimulation and weak crying
As the child grows older, symptoms may include:
- Food cravings and weight gain
- Short height stature and poor muscular mass
- Undeveloped sex organs
- Incomplete or delayed puberty
- Mild to moderate cognitive impairment
- Behavioral problems
- Speech problems
- Underactive thyroid (hypothyroidism)
- Adrenal insufficiency
- High risk of osteoporosis
What causes Prader-Willi syndrome?
Prader-Willi syndrome (PWS) is caused by genetic abnormalities on an unstable region on chromosome 15 that disrupts gene expression regulation. Throughout early fetal development, genetic changes that cause PWS occur in a section of the chromosome known as the Prader-Willi critical region (PWCR).
Specific chromosomal changes include:
- Deletions: Deletion in one area of the father’s chromosome 15 causes the loss of function of multiple genes in the majority of PWS cases. The missing paternal genes are generally involved in appetite and fullness regulation.
- Maternal uniparental disomy: Typically, a child inherits two copies of chromosome 15, one from each parent. In 25% of cases, a child with PWS has two copies of chromosome 15 from the mother and none from the father.
- Imprinting center defect: Due to a process known as “imprinting,” which impacts whether the cell can “read” a gene, genes in PWCR on the chromosome that originated from the mother are inactivated.
Researchers believe that PWS symptoms are caused by a malfunction in the hypothalamus, which is a part of the brain that regulates appetite, thirst, body temperature, pain, and waking and sleeping. Hypothalamic dysfunction can disrupt a range of physiological systems and pathways, resulting in various symptoms.
How is Prader-Willi syndrome diagnosed?
Prader-Willi syndrome (PWS) is typically diagnosed based on clinical symptoms, and a blood test is ordered to confirm the diagnosis.
Methylation analysis, which encompasses all the major genetic subtypes of PWS, is the preferred way of testing. Fluorescence in situ hybridization can be used to identify PWS caused by deletion.
In the unlikely case that laboratory testing does not confirm PWS, a clinical diagnosis can aid in the creation of a treatment strategy.
How is Prader-Willi syndrome treated?
People with Prader-Willi syndrome (PWS) may benefit from early diagnosis and treatment, which can improve their quality of life. The care team may include an endocrinologist, behavior specialist, dietitian, physical therapist, occupational therapist, mental health professional, geneticist, and other specialists as needed.
Since behavioral problems associated with PWS can disrupt life at school, social relationships, and family life, it is important for children with the condition to have support from loved ones.
Regular tests and consultation can help keep PWS symptoms under control. Support groups and counseling can help patients and their families cope with the emotional aspects of the disease.
Although treatment varies depending on symptoms, most children with PWS will need the following:
- Due to low muscle tone, many newborns with PWS have trouble eating. To help your baby gain weight, their pediatrician may recommend a high-calorie formula or specific feeding techniques and monitor your child’s progress.
- In children with PWS, human growth hormone therapy promotes proper development, improves muscular tone, and reduces body fat. Before initiating growth hormone medication, a sleep study is often suggested.
- Hormone replacement treatment may be started when your child reaches puberty, and it can help lower the risk of osteoporosis.
- Undescended testicles may require surgery.
- Sleep disorder treatment can help with daytime sleepiness and behavioral issues.
- A dietitian can assist you in developing a nutritious, low-calorie diet for your child to help manage their weight while maintaining sufficient nutrition.Supplemental vitamins or minerals may be required to ensure balanced nutrition.
- Increasing physical activity and exercise can aid in weight management and physical development.
Medically Reviewed on 3/2/2022
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