OBJECTIVES: Angelman syndrome (AS) is a rare genetic neurogenetic disorder causing developmental delays, speech impairments, movement disorder, and behavioral abnormalities. Systematic literature reviews (SLRs) were designed to summarize the evidence base and understand data gaps related to: (1) assessments of health-related quality of life (HRQoL) and health utility, and (2) healthcare resource utilization (HCRU) and/or costs associated with AS.

METHODS: Two SLRs, addressing HRQoL and HCRU in AS, were conducted in September 2021 using Medline and EMBASE. Screening and extraction (demographic, clinical and outcomes data) was performed by two independent reviewers, with screening conflicts resolved by a third reviewer.

RESULTS: Overall, 152 publications (61 HRQoL and 91 HCRU studies) met the search criteria. After abstract screening, 31 full-text articles were screened and 18 publications, extracted. Population and outcome definitions varied between studies. Twelve studies (publication: 1999-2021; sample sizes: 5-301) reported HRQoL data for AS patients or their families (7 studies) or in patients with behavioral disorders including AS (5 studies). Over 25 different instruments were used to assess HRQoL, most used was the ABC-C (Aberrant Behavior Checklist-Community; 3 studies). Five studies assessed sleep using different instruments. No studies reported health utilities. Six HCRU studies were identified (publication: 2002-2021; sample sizes: 27-527). Three studies reported hospitalization rates and two costing studies respectively reported testing costs and costs for patient and social care.

CONCLUSIONS: AS data on the impacts on HRQoL and HRCU is limited and inconsistent. Studies rely on small samples, owing to AS’ orphan disease nature, and high data heterogeneity is due to considerable differences in AS testing/reporting. Gaps include limited standardization in HRQoL instruments used, lack of health utilities and in-depth HCRU assessments, highlighting the need to further gain insights into the humanistic and economic burden of AS.