Table 4. Comparison of clinical characteristics in patients with SMN1 deletions only and those with both SMN1 and NAIP deletions.
| Characteristic | SMN1 deletion (n=24) | SMN1 and NAIP deletions (n=6) | p | RR (95% CI) |
|---|---|---|---|---|
| Males (n=11) | 9 | 2 | NS | |
| Age at symptom onset, mean±SD (range), months | 18.4±20.4 (0.1–96.0) | 1.9±1.7 (0.1–4.0) | 0.007 | |
| Clinical type (n=30) | 0.005 | |||
| Type 1 | 8 | 6 | ||
| Types 2+3 | 16 | 0 | ||
| Initial presentation (n=30) | 0.003 | 3.33 (1.53–7.27) | ||
| Respiratory difficulty and hypotonia | 6 | 5 | ||
| Developmental delay and gait disturbance | 18 | 1 | ||
| Clinical outcome (n=16) | 0.009 | 4.68 (1.48–14.8) | ||
| Survivors without ventilator | 10/12 | 0/4 | ||
| Died or on ventilator | 2/12 | 4/4 |
CI: confidence interval, NAIP: neuronal apoptosis inhibitory protein, NS: not significant, RR: relative risk, SMN1: survival of motor neuron 1.