- Prader Willi and Angelman Syndrome are neurodevelopmental disorders caused by a deletion of a region in chromosome 15 and are classically known as genomic imprinting disorders. These disorders are characterized by an imprinting center controlling the expression of selected genes in chromosome 15, therefore a deletion in these areas affect the expression of certain genes. Depending on the deletion occurring in the maternal or paternal chromosome the resulting disorder is Prader Willi if occurring in the paternal chromosome, or Angelman Syndrome if occurring in the maternal chromosome. Prader Willi Syndrome is caused by paternal deletion or maternal uniparental disomy of chromosome 15 and it is commonly characterized by diminished fetal activity, obesity, hypotonia, intellectual disability, short stature etc. Angelman Syndrome is originated from maternal deletion or paternal uniparental disomy and is characterized by jerky movements, abnormal laugher, sleep disturbances and characteristic facial features.
- The Igenomix Prader Willi and Angelman Syndrome Precision Panel can be used for an accurate and directed diagnosis ultimately leading to a better management and prognosis of the disease. It provides a comprehensive analysis of the genes involved in this disease using next-generation sequencing (NGS) to fully understand the spectrum of relevant genes involved.
- Feeding problems or failure to thrive
- Rapid weight gain
- Facial features: Narrow bifrontal diameter, almond-shaped palpebral fissures, narrow nasal bridge
- Developmental delay and severe intellectual deficit
- Speech impairment
- Tongue protrusion
- Paroxysms of laughter
- Abnormal sleep patterns
The clinical utility of this panel is:
- The genetic and molecular confirmation for an accurate clinical diagnosis of a symptomatic patient.
- Early initiation of treatment involving a multidisciplinary team in the form management of hypotonia and poor feeding, evaluation of hypogonadism, management of obesity, monitoring for scoliosis and therapy
- Risk assessment and genetic counselling of asymptomatic family members according to the mode of inheritance.
- Improvement of delineation of genotype-phenotype correlation.
Margolis, S. S., Sell, G. L., Zbinden, M. A., & Bird, L. M. (2015). Angelman Syndrome. Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics, 12(3), 641–650. https://doi.org/10.1007/s13311-015-0361-y
Butler, M. G., Miller, J. L., & Forster, J. L. (2019). Prader-Willi Syndrome – Clinical Genetics, Diagnosis and Treatment Approaches: An Update. Current pediatric reviews, 15(4), 207–244. https://doi.org/10.2174/1573396315666190716120925
Buiting, K., Williams, C., & Horsthemke, B. (2016). Angelman syndrome – insights into a rare neurogenetic disorder. Nature reviews. Neurology, 12(10), 584–593. https://doi.org/10.1038/nrneurol.2016.133
Bird L. M. (2014). Angelman syndrome: review of clinical and molecular aspects. The application of clinical genetics, 7, 93–104. https://doi.org/10.2147/TACG.S57386
Clayton-Smith, J., & Laan, L. (2003). Angelman syndrome: a review of the clinical and genetic aspects. Journal of medical genetics, 40(2), 87–95. https://doi.org/10.1136/jmg.40.2.87
Butler, M. G., Manzardo, A. M., & Forster, J. L. (2016). Prader-Willi Syndrome: Clinical Genetics and Diagnostic Aspects with Treatment Approaches. Current pediatric reviews, 12(2), 136–166. https://doi.org/10.2174/1573396312666151123115250
Bonello, D., Camilleri, F., & Calleja-Agius, J. (2017). Angelman Syndrome: Identification and Management. Neonatal network : NN, 36(3), 142–151. https://doi.org/10.1891/0730-08126.96.36.199
Madaan, M., & Mendez, M. D. (2021). Angelman Syndrome. In StatPearls. StatPearls Publishing.