Characteristics | Total (n=40) | One copy of SMN2(n=1) | Two copies of SMN2(n=25) | Three copies of SMN2(n=14) |

Sex, M:F, n | 18:22 | 1:0 | 10:15 | 7:7 |

Age at symptom onset | 3.0 (0.0–6.0) | 0.0 | 2.0 (0.0–6.0) | 4.5 (1.0–6.0) |

Age at nusinersen initiation | 20.0 (0.35–294.0) | 2.0 | 19.0 (0.35–140.0) | 25.3 (4.0–294.0) |

Disease duration before nusinersen | 17.5 (0.0–291.5) | 2.0 | 16.0 (0.35–140.0) | 17.5 (0.0–291.5) |

HINE-2 score | ||||

M0 | 0.0 (0.0–4.0), n=37 | 0.0, n=1 | 0.0 (0.0–2.0), n=24 | 2.0 (0.0–4.0), n=12 |

M6 | 2.5 (0.0–17.0), n=34 | 4.0, n=1 | 1.0 (0.0–11.0), n=22 | 4.0 (1.0–17.0), n=11 |

M10 | 4.0 (0.0–24.0), n=32 | 5.0, n=1 | 2.5 (0.0–20.0), n=20 | 4.0 (1.0–24.0), n=11 |

Time effect p value | <0.001 | / | <0.001 | 0.002 |

Delta M6–M0 | 2.0 (0.0–16.0), p<0.001 | 4.0 | 1.0 (0.0–11.0), p=0.002 | 2.0 (1.0–16.0), p=0.019 |

Delta M10–M0 | 3.0 (0.0–20.0), p<0.001 | 5.0 | 2.5 (0.0–20.0), p=0.003 | 3.0 (1.0–20.0), p=0.010 |

HINE-2 score (age ≤7 months old at onset of treatment) | ||||

M0 | 0.0 (0.0–4.0), n=13 | |||

M6 | 6.0 (2.0–16.0), n=11 | |||

M10 | 11.0 (3.0–24.0), n=11 | |||

Time effect p value | <0.001 | |||

Delta M6–M0 | 6.0 (2.0–12.0), p<0.001 | |||

Delta M10–M0 | 9.0 (3.0–20.0), p<0.001 | |||

HINE-2 score (age ≤2 years old at onset of treatment) | ||||

M0 | 0.0 (0.0–4.0), n=22 | |||

M6 | 5.0 (0.0–17.0), n=19 | |||

M10 | 9.0 (0.0–24.0), n=18 | |||

Time effect p value | <0.001 | |||

Delta M6–M0 | 4.0 (0.0–16.0), p<0.001 | |||

Delta M10–M0 | 7.5 (0.0–20.0), p<0.001 | |||

HINE-2 score (age >2 years old at onset of treatment) | ||||

M0 | 0.0 (0.0–2.0), n=15 | |||

M6 | 1.0 (0.0–4.0), n=15 | |||

M10 | 0.5 (0.0–7.0), n=14 | |||

Time effect p value | 0.002 | |||

Delta M6–M0 | 1.0 (0.0–2.0), p=0.003 | |||

Delta M10–M0 | 0.5 (0.0–5.0), p=0.013 |

* Data are listed as median (range) in months.

‡ One-way repeated measures ANOVA.

§ Paired t-test.

¶ Multiple regression demonstrated that there was significant difference in the changes of the HINE-2 scores, delta M6

**–**M0 and delta M10**–**M0, between the two groups with two and three*SMN2*copies with the standard coefficients β of 0.263 (p=0.003).† Three patients were not included in the HINE-2 M0 analysis, due to the following reasons: one patient did not have baseline HINE-2 performed; two patients did not have HINE-2 performed.

HINE-2, Hammersmith Infant Neurologic Examination Part 2 motor milestones score; M0, before treatment; M6, 6 months of treatment; M10, 10 months of treatment; SMN, survival motor neuron.