Angelman Syndrome Natural History Study

Quick Overview

The Natural History Study is a longitudinal observational study conducted over many years to gather long-term data on Angelman Syndrome. This data is crucial for future therapeutic development and drug trials. The study collects data prospectively, minimising variability in data collection. The study is critical for understanding the natural course of the disease, developing endpoints for clinical trials, and generating data for drug development. The study also helps build expertise among clinicians and infrastructure for launching clinical trials. The study began in 2006 and enrolled 302 children and adults with Angelman Syndrome over eight years. The study has faced challenges such as low enrolment of adults and attrition. In 2017, the study was relaunched with improvements including standardised measures, an online portal, and the use of home videos. The study is currently being conducted at several sites.


The Natural History Study is an observational study that is longitudinal. The aim is to collect long-term data that pharmaceutical companies and other investigators can use for future therapeutic development. The study complements the patient registry and is absolutely critical for drug development.

Importance of the Natural History Study

The Natural History Study is important because it allows us to understand the natural cause of the disease. This understanding helps us distinguish between side effects and natural disease progression when a compound is being tested in a clinical trial. It also helps us develop endpoints for clinical trials.

Participation in the Natural History Study

Participation in the Natural History Study helps us learn about Angelman Syndrome. It is only through having networks of investigators in the Natural History Study that we can build expertise among clinicians in Angelman Syndrome. This is absolutely critical when it comes to running clinical trials because you want experts to be running clinical trials.

The Need for a Natural History Study

The Natural History Study is needed because control groups in clinical trials are necessarily homogeneous, meaning you isolate them and you study a very small subset of patients. In a Natural History Study, we take all comers, so you get a much better representation of Angelman Syndrome.

The History of the Natural History Study

The Natural History Study was started in 2006, funded by the NIH, and we enrolled a number of patients through all the study sites. This was led by Dr. Lynne Bird in San Diego, and we had this for eight years until we ran out of funding initially.

Challenges and Improvements

There are challenges in conducting the Natural History Study. One of the challenges is the low enrolment of adults and attrition. To improve the study, we engaged with all the Angelman Syndrome clinics, and we asked all the stakeholders, what would you like to see? We introduced an online portal and allowed for telemedicine visits.


The Natural History Study is a critical part of understanding Angelman Syndrome and developing future treatments. We are grateful to all the families who have participated in the study and encourage more to do so. We are also thankful to our sponsors and investigators who have made this study possible.

Talk details

  • Title: Angelman Syndrome Natural History Study
  • Author(s): Wen-Han Tann
  • Author(s)’ affiliation: Boston’s Children Hospital
  • Publication date: 2019-09-06
  • Collection: 2019 ASF Family Conference