The disease is slowly progressive and compatible with a normal life span. Asymptomatic affected members of a family have no restrictions. In a survey, 61 of 126 affected adults were currently working, only 9 needed adjustments for disease-related handicaps, and 85% considered their jobs satisfying (Wavers et al 1993).
Medical complications are few. Twenty percent of patients above the age of 50 will eventually use a wheelchair. A prospective study of genetically confirmed patients with FSHD examined the incidence of restrictive lung disease in patients with FSHD (Scully et al 2014). About 10% showed a restrictive pattern on pulmonary function testing, with none of the 61 patients requiring ventilator support. Clinically significant respiratory failure requiring noninvasive or invasive ventilator support occurs in about 1% of patients (Wohlgemuth et al 2004). Predisposing factors for restrictive lung disease include wheelchair dependence, pelvic girdle weakness, kyphoscoliosis or lumbar lordosis, and pectus excavatum (Wohlgemuth et al 2004; Scully et al 2014). Patients with predisposing factors should have periodic pulmonary function testing.
Severe childhood onset FSHD, typically with large deletions (ie, residual D4Z4 allele size of 10 to 18 kb), are at higher risk of developing a potentially preventable exudative retinopathy also known as Coat disease; such patients need periodic surveillance with dilated indirect ophthalmoscopy (Statland et al 2013). These same patients are also at risk for symptomatic hearing loss and should have routine audiometric testing. Moreover, hearing loss can be progressive, and children with large deletions should continue to be monitored even if they passed newborn hearing screening (Lutz et al 2013).
Pregnancy is usually tolerated well, but some women later have more difficulty caring for children (Rudnik-Schoneborn et al 1997; Ciafaloni et al 2006).