The following report from the MHC-database is based on the latest version of the Mun-H-Center Observation Chart that has been in use since 2008. Please note, that this report exclude children younger than 3 years.
Reports based on the original forms (1996-2008) are presented at the bottom of this page - below the description of the diagnosis
Estimated occurrence
1:15 000 – 25 000 live births.
Etiology
Chromosomal aberration on chromosome 15. The gene or genes that cause the syndrome have not yet been identified.
General symptoms
There are great variations between different individuals and different ages. Pronouncedly poor muscle tone/hypotonicity from birth. After the age of one or two, distinct eating disorder occur, with an insatiable appetite despite a low need of energy (approximately 50-60% of what is considered normal). Without a special diet, this results in extreme obesity and an increased risk of type II diabetes. Most of these individuals are mildly to moderately intellectually impaired and delayed motor development is common. There is an increased risk of behavior problems. Individuals with PWS often have short stature and underdeveloped sexual organs (hypogonadism).
Orofacial/odontological symptoms
Characteristic facial features are associated with the diagnosis. Muscle laxity in newborns leads to most PWS infants being unable to be breastfed. Many require a special bottle or tube feeding. Delayed speech and language development and problems with oral motor skills are common. Many suffer from dry mouth. Narrow nasal and throat airways may result in snoring and an increased risk of sleep apnea (frequent suspension of breathing while asleep). Delayed teething, defective tooth enamel, an excessive number of teeth and small teeth have all been reported. A high, arched palate and malocclusion are common. Some individuals have tooth grinding. There is an increased risk of caries owing to the eating disorder and dry mouth.
Orofacial/odontological treatment
- Early contact with dental services for intensified prophylactic care and oral hygiene information is essential.
- Regular check-ups of dental and jaw development. Orthodontist should be consulted when needed.
- Tooth grinding should be followed up, and be managed with a splint when necessary.
- Training in oral motor skills may be relevant.
- Speech, language and communication training are often justified.
- Snoring problems should be followed up by a physician.
Sources
The rare disease database of the Swedish National Board of Health and Welfare.
The MHC database - The Mun-H-Center database on oral health and orofacial function in rare diseases.
The Newsletter from the Ågrenska center.
Scientific papers (abstracts)
Thesis
”Prader-Willi Syndrome; Epidemiological, Behavioural, Language and Neurochemical Aspects”
Åkfeldt, A., Institute of Clinical Sciences and Institute of Clinical Neuroscience, Göteborg University
