Table 1 Distribution of SMN2 copy number by SMA type
Number of SMN2 copies | SMA1 n = 140 (% of SMA1 patients) | SMA2 n = 182 (% of SMA2 patients) | SMA3 n = 344 (% of SMA3 patients) | SMA4 n = 6 (% of SMA4 patients) |
|---|---|---|---|---|
1 | 2 (1.4%) | 1 (0.5%) | 0 | 0 |
2 | 53 (38%) | 14 (7.7%) | 21 (6%) | 0 |
3 | 80 (57%) | 149 (82%) | 185 (54%) | 1 (17%) |
4 | 5 (3.6%) | 18 (10%) | 138 (40%) | 5 (83%) |