Background: Facioscapulohumeral muscular dystrophy (FSHD) is a rare genetic muscular dystrophy characterized by progressive muscle weakness and atrophy. FSHD typically manifests in the second decade of life, though onset can range from infancy to late adulthood. Although FSHD is referred as a non-life-threatening disease, limited evidence supports this claim. Assessing the mortality impact of FSHD is essential for understanding its severity and broader implications. Thus, we conducted a systematic literature review (SLR) to synthesize evidence regarding mortality and life expectancy associated with FSHD.
Methods: MEDLINE and Embase were searched via Ovid for studies published from inception to August 20, 2024. Studies besides editorials, notes, letters, and case reports on mortality were included after screening. Study information, participant characteristics, and mortality data were extracted. Quality of the included cohort studies was appraised using the Newcastle-Ottawa Scale.
Results: Eight studies were included in the SLR. A total of 1038 patients with FSHD (classical FSHD [onset after 20 years of age]: n = 1002, 96.5%; early-onset infantile or childhood FSHD [onset before 5 years of age]: n = 36, 3.5%) were assessed between 1979 and 2016, primarily from single medical centers or locations across five countries. Deaths were reported in 83/1002 (8.3%) patients with classical FSHD and 7/36 (19.4%) patients with early-onset infantile or childhood FSHD across the eight studies. The mean age of death ranged from 63.0 to 65.6 years in patients with classical FSHD and 12.0 to 31.0 years in patients with early-onset infantile or childhood FSHD across seven studies. The primary cause of death was respiratory- or cardiac-related, if reported.
Conclusion: Patients with FSHD may have a detrimental effect on survival, especially when the disease onset occurs during childhood. Future research is needed to generate robust evidence to better capture the true effect of FSHD on life expectancy and mortality.