Figure 3.

Females are more likely to progress to wheelchair use overall. Log-rank analysis of baseline and longitudinal data shows that (A) females were more likely at all ages to use a wheelchair compared to males, with a median age of wheelchair use of 59 (95% CI: 56, 62) whereas males had a median age of wheelchair use at 64 (95% CI: 62, 68). Females have a shorter length of time from age at diagnosis to age of wheelchair use (B), with a median difference of 23 years for females (95% CI: 19, 26) and 32 years for males (95% CI: 29, 37). There is no significant difference between D4Z4 repeat length and length of time form diagnosis to wheelchair use (P = 0.2) (C), but when separated by gender we again see that females were more likely than males to progress to wheelchair use (P = 4 × 10⁻⁴) (D). Females in the 1–3 D4Z4 repeat category have a median time of progression to wheelchair use of 23 years (95% CI: 15, 31) whereas males with 1–3 D4Z4 repeats have a median time of progression to wheelchair use of 28 years (95% CI: 20, n/a). Females in the 4–7 D4Z4 repeat category had a median time of progression to wheelchair use of 22 years (95% CI: 18, 27) whereas males had a median time of progression of 33 years (95% CI: 29, 40). Females in the 8–10 D4Z4 repeat category had a median time of progression to wheelchair use of 20 years (95% CI: 12, n/a) whereas males had a median time of progression of 28 years (95% CI: 18, 54).