DESCRIPTION
Humans have 46 chromosomes. These include:
- Chromosomes 1 through 22
- The sex chromosomes X and Y
We inherit one copy of chromosomes 1 through 22 from our mother. We inherit another copy from our father. Males inherit X and Y chromosomes. Females inherit X and X. These chromosomes carry our genetic information.
PWS can occur when a specific region of chromosome 15 inherited from the father is deleted. This is the cause in approximately 70% of people with PWS.
It can also occur if both copies of chromosome 15 are inherited from the mother. In this case, the person lacks a copy of chromosome 15 from their father. This is called maternal uniparental disomy.
CAUSES
PWS occurs when a region of a specific chromosome is deleted or not functioning. The region is part of chromosome 15 inherited from the father. This can happen in three different ways:
- Deletion. A part of chromosome 15 is missing. This is the most common cause.
- Maternal uniparental disomy (UPD). A child inherits two chromosome 15s from their mother. They inherit none from their father.
- Imprinting error. Chromosome 15 is intact. However, the PWS region is not working properly. This is due to genetic variation that “turns off” the region.
LABORATORY INVESTIGATIONS
The following are key to diagnosis:
- A medical history evaluation
- A clinical examination
One clue may be decreased fetal movement during pregnancy. Another can be an abnormal fetal position at delivery. This may require assistance or a C-section.
Sometimes more tests are necessary to diagnosis PWS. These may include:
- Genetic testing. This tests for the presence of the PWS region. It also looks for variation of the chromosomal region.
- Magnetic resonance imaging (MRI). A picture of the brain is examined for associated abnormalities.
TREATMENT AND THERAPIES
Currently, there is no cure for PWS. However, supportive care is available.
Feeding support.
Many children will need special nipples for bottles. They may also need a feeding tube in infancy and early childhood. Children may need to work with a dietician for obesity later in life.
Vitamin supplementation.
Supplements can increase low levels of calcium and vitamin D. Both are important for bone health.
Hormonal therapy.
Endocrine problems may occur. Certain hormones can correct these. Hormones may include:
- Testosterone
- Human chorionic gonadotropin
- Growth hormone
Developmental therapy.
Therapies may involve:
- Speech therapy
- Physical therapy
- Occupational therapy
Psychosocial support for families.
Support may involve:
- Parent groups
- A social worker
- A psychotherapist
Individualized education plan (IEP).
An IEP is set up with a school. It gives a child the best possible education.
Back bracing and/or surgery.
Treatments may be needed for:
- Scoliosis
- Other abnormalities affecting specific organs
Comprehensive eye exam.
Patients with abnormal eye findings may require corrective glasses or surgery.
Comprehensive sleep study.
If their sleep is abnormal, a patient may require surgery. Surgeries can include removal of the tonsils or adenoids (glands at the back of the nasal cavity). They may also need a breathing machine called a continuous positive airway pressure (CPAP) machine.
Resources
Foundation for Prader-Willi Research
The Foundation for Prader-Willi Research (FPWR) was established with one aim in mind: to eliminate the challenges of Prader-Willi syndrome through the advancement of research and therapeutic development. Some of the many resources FPWR provides are: the First Steps Parents Package, an opportunity to sign up for the Global PWS Registry, information on PWS Clinical Trials, a Family Conference, and steps for effective advocacy.
International Prader-Willi Syndrome Organization (IPWSO)
The mission of the International Prader-Willi Syndrome Organization (IPWSO) is to unite the global PWS community to collectively find solutions to the challenges of the syndrome. IPWSO also aims to support and advocate for people with PWS and their families, PWS associations, and professionals who work with people with PWS. Their website provides resources and information for families, and the latest medical and scientific research and information for health professionals. IPWSO also shares international knowledge among professional service providers throughout the world.
Prader-Willi Syndrome Association | USA
The mission of the Prader-Willi Syndrome Association | USA (PWSA | USA) is to enhance the quality of life of and empower those affected by Prader-Willi syndrome. They provide family and medical support to individuals diagnosed with Prader-Willi syndrome, their families, and care providers. PWSA | USA also focuses on Advocacy, Awareness, and Research. Private Facebook groups can be found for: PWSA | USA Birth to Three, PWSA | USA Three to Five, PWSA | USA Parents of Teens and Older, PWSA | USA Grandparents, PWSA | USA Dads, and PWSA |USA Siblings.
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