Prader-Willi Syndrome
Prader-Willi Syndrome (PWS) is a complex genetic disorder that can affect both males and females. Individuals with the condition can present with a wide range of physical, cognitive and behavioural symptoms, in varying degrees. PWS results from deletion of a region on the paternal chromosome 15 or the presence of two maternal copies of chromosome 15 (uniparental disomy). In rare cases, PWS can also result from an imprinting defect or a mutation in the imprinting centre on chromosome 15.
The symptoms of Prader-Willi Syndrome can vary in severity and may include:
- Hyperphagia and obesity: Individuals with PWS have an insatiable appetite and a constant feeling of hunger, leading to excessive eating and obesity.
- Hypotonia: Infants with PWS often have low muscle tone, resulting in poor sucking ability, weak cry, and delayed motor development.
- Growth hormone deficiency: Many individuals with PWS have a deficiency in growth hormone, which can lead to short stature and delayed puberty.
- Cognitive and intellectual disabilities: People with PWS will typically have mild to moderate intellectual disability. They may also have learning difficulties and exhibit deficits in abstract thinking and problem-solving skills.
- Behavioural and emotional difficulties: Individuals with PWS may display behavioural difficulties such as stubbornness, temper tantrums, obsessive-compulsive tendencies, and a tendency to hoard food. They may also experience mood swings, anxiety, and difficulty with emotional regulation.
PWS and ASD have some overlapping characteristics. For example, social and communication difficulties are features of both conditions, although individuals with PWS tend to have a stronger desire for social interaction than do those with ASD. Similarly, repetitive behaviours and a preference for “sameness” are also features of both conditions. However, there are a number of important distinctions between ASD and PWS. PWS is relatively rare compared to autism and is caused by specific genetic abnormalities on chromosome 15 (whereas autism is a complex neurodevelopmental disorder with research indicating multiple genetic and epigenetic factors in its pathogenesis). Furthermore, one of the distinctive features of PWS is the insatiable appetite and the tendency to overeat, leading to obesity, although this symptom is not associated with autism. It is possible for an individual with PWS to also meet the criteria for a diagnosis of ASD.
PWS is diagnosed by genetic testing and examination of physical, cognitive and behavioural presentations. The treatment and intervention strategies for PWS are focused on managing the symptoms and addressing the various challenges associated with the disorder. This will typically involve a multidisciplinary approach, which can include some or all of the following professionals: paediatricians, endocrinologists, behavioural therapists, dietitians, physiotherapists, occupational therapists and speech & language therapists.
Reference
Angulo, M.A., Butler, M. G., & Cataletto M. E. (2015). Prader‑Willi syndrome: A review of clinical, genetic, and endocrine findings. Journal of Endocrinological Investigation, 38, 1249–1263. doi: 10.1007/s40618-015-0312-9
