Frequency of SMN1 copy number across various ethnicities
| Ethnicity | 1 copy | 2 copies | 3 copies | Total n | |||
| n | Frequency (95% CI) | n | Frequency (95% CI) | n | Frequency (95% CI) | ||
| Caucasian | 28 | 0.027 (0.019 to 0.039) | 935 | 0.910 (0.89 to 0.93) | 65 | 0.063 (0.05 to 0.08) | 1028 |
| Ashkenazi Jewish | 22 | 0.022 (0.015 to 0.033) | 827 | 0.825 (0.80 to 0.85) | 153 | 0.153 (0.13 to 0.18) | 1002 |
| Asian | 18 | 0.018 (0.011 to 0.028) | 897 | 0.873 (0.85 to 0.89) | 112 | 0.109 (0.09 to 0.13) | 1027 |
| African American | 11 | 0.011 (0.006 to 0.019) | 529 | 0.521 (0.49 to 0.55) | 475 | 0.468 (0.44 to 0.50) | 1015 |
| Hispanic | 8 | 0.008 (0.004 to 0.015) | 870 | 0.845 (0.82 to 0.87) | 152 | 0.148 (0.13 to 0.17) | 1030 |