Institute Activities and Advances
Intellectual and Developmental Disabilities Branch -supported research, both from the Angelman, Rett, and Prader-Willi Syndromes Consortium and from individual projects, has led to the following advances in PWS research:
- Researchers have created new mouse models for Angelman syndrome that also affect the imprinting center shared with PWS.
- Research shows that many epigenetic disorders share features, including altered MECP2 expression in Prader-Willi, Rett, and Angelman syndromes (Nagarajan et al., 2006). Mutations on the MECP2 gene cause most cases of Rett syndrome, a disorder characterized by a loss of language and of cognitive and fine motor skills that occurs mostly in girls.
- By placing a deletion of the chromosome 15 imprinting center on a different genetic strain, researchers were able to create a mouse model for studying PWS (Chamberlain et al., 2004).
- To address the problem of excessive eating that occurs in PWS, researchers developed a questionnaire to study hyperphagia (Dykens et al., 2007), defined as excessive hunger and abnormally large intake of solid foods. The same group of investigators also detected neural differences in visual responses to food stimuli among people with different forms of PWS based on the food's composition and suitability for consumption.
The Unit on Metabolism and Neuroendocrinology, which is within the Program on Developmental Endocrinology and Genetics in the NICHD's Division of Intramural Research (DIR), also conducts studies related to some of the features of PWS, specifically those characteristics associated with food behaviors and metabolism. Recent findings include low levels of brain-derived neurotrophic factor, a chemical that plays a role in the leptin signaling pathway that regulates appetite and energy balance. For more information on this research and other findings from the unit, visit http://2012annualreport.nichd.nih.gov/umn.html.
In addition, the Section on Growth and Obesity, also within the DIR, conducts research to understand the metabolic and behavioral factors involved in determining regulation of body weight and body composition during childhood. This work includes studies of brain-derived neurotrophic factor and leptin as well as of hyperphagia and other conditions and health problems related to obesity. Visit http://2012annualreport.nichd.nih.gov/sgo.html for more on this research.
Other Activities and Advances
- In 2009, the NICHD helped to sponsor the First International Conference on Hyperphagia as a way to learn more about hunger and excessive hunger, the drive to overeat, and obesity associated with certain intellectual and development disabilities (IDDs), including Prader-Willi syndrome. Objectives included discussion of both similar and unique aspects of hyperphagia across IDDs, facilitation of more accurate and earlier diagnosis of hyperphagia, and understanding of the management and quality-of-life issues faced by families affected by hyperphagic disorders. Watch conference presentations from the Second International Conference on Hyperphagia in 2012.
- Eunice Kennedy Shriver Intellectual and Developmental Disabilities Research Centers (EKSIDDRCs) support basic, clinical, and translational researchers whose goals are to advance understanding of a variety of conditions and topics related to IDDs, including Prader-Willi syndrome. The Centers' research services include information technology, bioinformatics, and biostatistics as well as gene array, proteomics, and behavioral and clinical core services.
- Rare Diseases Clinical Research Network Patient Registry is a database where people with rare genetic diseases can register to be contacted about clinical trials and to be given updates on the progress of research projects.