To identify risk factors for wheelchair use (WC) in people with facioscapulohumeral muscular dystrophy (FSHD) participating in the United States FSHD Registry.

FSHD is a dominantly inherited, slowly progressive muscular dystrophy caused by deletion of repeats in the D4Z4 region on chromosome 4. Normal individuals have >10 repeats; patients with FSHD type 1 have between 1-10 repeats. There is limited data about predictors of functional burden.

Small allele size (1-3 D4Z4 repeat units) was associated with earlier diagnosis (median 14 years, 95% confidence limit 11, 17), facial weakness as the initial symptom (53.7%), and higher risk of WC.  Our AI final model showed accuracy 0.79 and AUC 0.85, and revealed only a small contribution of genetics (lower risk for WC with 8-10 D4Z4 repeat units).  The most significant predictors of WC were: disease duration, number of medications, age at diagnosis or symptom onset, and medical comorbidity (e.g. breathing difficulties, pneumonia, or arthritis).  When looking at classes of medications, the model predicated that all classes influenced towards (+) WC except for amino acids.