Tracking changes in Angelman syndrome over 12 months

A Longitudinal Natural History Study of Adults and Children With Angelman Syndrome

Observational Massachusetts General Hospital · NCT07417137

This study will see how developmental skills, behavior, sleep, and brain activity change over one year in children and adults with a genetically confirmed diagnosis of Angelman syndrome.

Quick facts

Study typeObservational
Enrollment40 (estimated)
Ages1 Year and up
SexAll
SponsorMassachusetts General Hospital Academic / other
Locations1 site (Lexington, Massachusetts)
Trial IDNCT07417137 on ClinicalTrials.gov

What this trial studies

This is a longitudinal natural history study enrolling about 40 people with genetically confirmed Angelman syndrome, enriched for adolescents. Participants attend five in-person visits over 12 months (baseline and roughly every 13 weeks) to complete standardized tests of communication, motor skills, adaptive behavior, and clinical history. Neurophysiology and sleep are measured with EEGs and home actigraphy while caregivers complete questionnaires about behavior, health, and sleep. The study aims to generate normative data and link biomarker changes to clinical outcomes to better inform future trial design and diagnostic or therapeutic development.

Who should consider this trial

Good fit: Ideal candidates are people aged one year or older with a confirmed genetic diagnosis affecting UBE3A and a caregiver or study partner able to attend five in-person visits over 12 months.

Not a fit: People without a confirmed UBE3A-related genetic diagnosis, those unable to travel to the study site or provide a study partner, and those seeking immediate therapeutic benefit rather than observational data are unlikely to gain direct benefit.

Why it matters

Potential benefit: If successful, the study could improve how future clinical trials are designed for Angelman syndrome and help identify EEG and sleep biomarkers that guide targeted treatments.

How similar studies have performed: Other natural history and biomarker studies in Angelman syndrome have reported EEG and sleep patterns of interest, but datasets vary in size and adolescent-focused longitudinal data remain limited.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* The participant has a primary clinical diagnosis of Angelman syndrome with documented genetic variation(s) affecting the function of the UBE3A gene within the human 15q11.2-q13.3 locus. Co-occurring conditions (e.g., autism spectrum disorder, cerebral palsy, intellectual disability) are permitted; however, Angelman syndrome must be the primary clinical diagnosis.
* The participant is male or female (assigned sex at birth) and aged ≥1 year at the initial study visit.
* The participant has a study partner who meets the study partner criteria below.
* The participant, if unable to provide informed consent, has an appropriate surrogate who is at least 18 years of age and willing and able to provide informed consent on behalf of the participant in accordance with current International Council for Harmonisation (ICH) guidelines and applicable institutional regulations.

Individuals must satisfy the following criteria to be enrolled as study partners:

* The study partner is a parent or primary caregiver who is at least 18 years of age.
* The study partner has consistent contact with the participant and, in the opinion of the investigator, is sufficiently knowledgeable about the participant's ongoing condition to provide accurate and current information.
* The study partner has sufficient English-language proficiency to complete study partner assessments.
* The study partner is willing and able to provide informed consent on their own behalf in accordance with ICH guidelines and applicable institutional regulations.
* The study partner is, in the opinion of the investigator, reliable and competent; willing and able to accompany the participant to all study visits and comply with study procedures; reachable by telephone or email as needed; and sufficiently knowledgeable about the participant's ongoing condition(s) to provide accurate and current information regarding the participant's health and well-being.

Exclusion Criteria:

* The participant has at least one additional known genetic abnormality outside the human 15q11.2-q13.3 locus causing a probable or known developmental disability.
* At least one standard-of-care treatment (medication or adjunctive therapy) used by the participant was changed during the 28 days (4 weeks) prior to the first study visit. Treatments include, but are not limited to, doses of anti-epileptic medications, behavioral management medications, sleep medications, gabapentin, cannabidiol, special diets, supplements, speech therapy, occupational therapy, applied behavioral analysis (ABA), psychosocial interventions, physical therapy, or nutritional support.
* The participant has unstable epilepsy, defined as having an emergency department visit or hospitalization for seizure-related concerns within the 28 days (4 weeks) preceding the initial study visit.
* The participant is of childbearing potential and is either pregnant, breastfeeding, or not using an adequate method of contraception; abstinence is acceptable.
* The participant has a clinically relevant history of malignancy; clinically significant abnormal test results; clinically significant cardiovascular, hematologic, hepatic, muscular, neurologic, or renal disease; or has experienced other clinical events which, in the opinion of the investigator, render participation unsuitable.
* The participant has a lifetime history of treatment with any cell- or gene-based therapy, including antisense oligonucleotides or gene-editing therapies.
* The participant has received any investigational therapy other than a cell- or gene-based therapy within 28 days or 5 half-lives (whichever is longer) preceding the initial study visit.
* The participant is currently enrolled or plans to enroll in an interventional study involving an investigational agent or device during the planned observation period.
* The participant has a known contraindication to electroencephalography, actigraphy, or any other study procedure described in the schedule of assessments.
* The participant or study partner is, in the opinion of the investigator, unsuitable for participation in any other way, including an inability to fulfill study requirements.

Where this trial is running

Lexington, Massachusetts

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Angelman SyndromeAngelman syndromeAngelmanGLOW-ASAS
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.