Evaluation of the safety and tolerability of a nutritional Formulation in patients with ANgelman Syndrome (FANS): study protocol for a randomized controlled trial

Trials. 2020 Jan 9;21(1):60. doi: 10.1186/s13063-019-3996-x.


Background: Ketogenic and low-glycemic-index diets are effective in treating drug-resistant seizures in children with Angelman syndrome. Cognition, mobility, sleep, and gastrointestinal health are intrinsically linked to seizure activity and overall quality of life. Ketogenic and low-glycemic diets restrict carbohydrate consumption and stabilize blood glucose levels. The ketogenic diet induces ketosis, a metabolic state where ketone bodies are preferentially used for fuel. The use of exogenous ketones in promoting ketosis in Angelman syndrome has not been previously studied. The study formulation evaluated herein contains the exogenous ketone beta-hydroxybutyrate to rapidly shift the body towards ketosis, resulting in enhanced metabolic efficiency.

Methods/design: This is a 16-week, randomized, double-blind, placebo-controlled, crossover study to assess the safety and tolerability of a nutritional formula containing exogenous ketones. It also examines the potential for exogenous ketones to improve the patient's nutritional status which can impact the physiologic, symptomatic, and health outcome liabilities of living with Angelman syndrome.

Discussion: This manuscript outlines the rationale for a study designed to be the first to provide data on nutritional approaches for patients with Angelman syndrome using exogenous ketones.

Trial registration: ClinicalTrials.gov, ID: NCT03644693. Registered on 23 August 2018. Last updated on 23 August 2018.

Keywords: Angelman syndrome; Children; Exogenous ketone; Ketogenic diet; Ketone ester; Ketone supplement; Ketosis; Placebo-controlled trial.

Publication types

  • Clinical Trial Protocol

MeSH terms

  • 3-Hydroxybutyric Acid / administration & dosage
  • Angelman Syndrome / diet therapy*
  • Angelman Syndrome / metabolism
  • Cross-Over Studies
  • Diet, Carbohydrate-Restricted
  • Diet, Ketogenic*
  • Double-Blind Method
  • Glycemic Index
  • Humans
  • Ketones / administration & dosage*
  • Nutritional Status
  • Randomized Controlled Trials as Topic*


  • Ketones
  • 3-Hydroxybutyric Acid

Associated data

  • ClinicalTrials.gov/NCT03644693