Facioscapulohumeral dystrophy (FSHD) type 1 – From infantile to late adult onset

Abstract

Objective: To describe and analyze the clinical characteristics of eight Chinese patients with genetically confirmed facioscapulohumeral muscular dystrophy type 1 (FSHD1) in Hong Kong. Method: We retrospectively collected and analysed the clinical data of the eight patients. Six adult patients were referred to the Clinical Genetic Service, the Department of Health from different hospitals, and two paediatric patients were evaluated in the Department of Paediatrics and Adolescent Medicine, the University of Hong Kong. All had genetic testing using Southern blot and hybridization overseas, either self-financed or through research collaboration with donation funding. Results: All eight patients have FHSD1 with D4Z4 contraction. One patient has infantile-onset FSHD1. Six patients had symptom onset in the adolescent age and one during late adulthood. Four patients (50%) have a positive family history. Asymmetrical muscle involvement is common and supported by muscle MRI findings. Increased difficulties in walking over time is evident. All four patients aged >40 years require a walking stick (median age: 47.5 years of age), and two also occasionally use a wheelchair. There is a notable delay in diagnosis after the onset of symptoms (median: 16 years; range: 2-44 years). Conclusions: FSHD1, a progressive hereditary muscle disease, affects both paediatric and adult patients. The significant delay in diagnosis may be due to lack of awareness, under-referral and the lack of local genetic diagnostic services for FSHD. There is an imminent need to establish a FSHD genetic diagnostic service in our public healthcare system to provide early diagnosis and timely management for patients with FSHD.