Table 2 Patient clinical characteristics and SMN copy number information (N = 62)
Characteristic | SMA typea | Total N = 62 | |||
|---|---|---|---|---|---|
1 (n = 9) | 2 (n = 13) | 3 (n = 24) | 4 (n = 16) | ||
Age of onset | |||||
≤ 2 years | 4 (44.4) | 5 (38.5) | 7 (29.2) | 0 (0) | 16 (25.8) |
3–10 | 0 (0) | 0 (0) | 4 (16.7) | 0 (0) | 4 (6.5) |
11–20 | 0 (0) | 0 (0) | 0 (0) | 1 (6.3) | 1 (1.6) |
21–30 | 0 (0) | 0 (0) | 0 (0) | 1 (6.3) | 1 (1.6) |
31–40 | 0 (0) | 0 (0) | 0 (0) | 3 (18.8) | 3 (4.8) |
41–50 | 0 (0) | 0 (0) | 0 (0) | 2 (12.5) | 2 (3.2) |
≥ 51 | 0 (0) | 0 (0) | 0 (0) | 5 (31.3) | 5 (8.1) |
Unknown | 5 (55.6) | 8 (61.5) | 13 (54.2) | 4 (25.0) | 30 (48.4) |
SMN1 exon 7 copy number | |||||
0 copies | 2 (22.2) | 2 (15.4) | 3 (12.5) | 0 (0) | 7 (11.3) |
≥ 1 copy | 7 (77.8) | 11 (84.6) | 21 (87.5) | 16 (100) | 55 (88.7) |
Maximum motor function | |||||
Climbing up stairs | 0 (0) | 0 (0) | 17 (70.8) | 15 (93.8) | 32 (51.6) |
Walking independently | 0 (0) | 0 (0) | 7 (29.2) | 1 (6.3) | 8 (12.9) |
Walking with assistance | 0 (0) | 6 (46.2) | 0 (0) | 0 (0) | 6 (9.7) |
Stands with assistance | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) |
Shuffling in sitting position | 0 (0) | 6 (46.2) | 0 (0) | 0 (0) | 6 (9.7) |
Pivots (rotate) (on the spot) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) |
Sitting independently | 0 (0) | 1 (7.7) | 0 (0) | 0 (0) | 1 (1.6) |
Head upright all the time | 5 (55.6) | 0 (0) | 0 (0) | 0 (0) | 5 (8.1) |
Unable to maintain head upright | 4 (44.4) | 0 (0) | 0 (0) | 0 (0) | 4 (6.5) |
Current motor function | |||||
Climbing up stairs | 0 (0) | 0 (0) | 10 (41.7) | 6 (37.5) | 16 (25.8) |
Walking independently | 0 (0) | 0 (0) | 5 (20.8) | 5 (31.3) | 10 (16.1) |
Walking with assistance | 0 (0) | 4 (30.8) | 3 (12.5) | 1 (6.3) | 8 (12.9) |
Stands with assistance | 0 (0) | 2 (15.4) | 3 (12.5) | 1 (6.3) | 6 (9.7) |
Shuffling in sitting position | 0 (0) | 5 (38.5) | 1 (4.2) | 1 (6.3) | 7 (11.3) |
Pivots (rotate) (on the spot) | 0 (0) | 0 (0) | 1 (4.2) | 0 (0) | 1 (1.6) |
Sitting independently | 0 (0) | 0 (0) | 0 (0) | 1 (6.3) | 1 (1.6) |
Head upright all the time | 4 (44.4) | 2 (15.4) | 1 (4.2) | 1 (6.3) | 8 (12.9) |
Unable to maintain head upright | 4 (44.4) | 0 (0) | 0 (0) | 0 (0) | 4 (6.5) |
Unknown | 1 (11.1) | 0 (0) | 0 (0) | 0 (0) | 1 (1.6) |
Tracheostomy | |||||
Yes | 3 (33.3) | 1 (7.7) | 1 (4.2) | 1 (6.3) | 6 (9.7) |
No | 5 (55.6) | 12 (92.3) | 23 (95.8) | 15 (93.8) | 55 (88.7) |
Unknown | 1 (11.1) | 0 (0) | 0 (0) | 0 (0) | 1 (1.6) |
SMN1 | |||||
Exon 7 copy number | |||||
0 | 2 (22.2) | 2 (15.4) | 3 (12.5) | 0 (0) | 7 (11.3) |
1 | 3 (33.3) | 0 (0) | 4 (16.7) | 0 (0) | 7 (11.3) |
2 | 3 (33.3) | 10 (76.9) | 17 (70.8) | 15 (93.8) | 45 (72.6) |
3 | 1 (11.1) | 1 (7.7) | 0 (0) | 1 (6.3) | 3 (4.8) |
Exon 8 copy number | |||||
1 | 5 (55.6) | 2 (15.4) | 6 (25.0) | 0 (0) | 13 (21.0) |
2 | 3 (33.3) | 10 (76.9) | 18 (75.0) | 14 (87.5) | 45 (72.6) |
3 | 1 (11.1) | 1 (7.7) | 0 (0) | 2 (12.5) | 4 (6.5) |
SMN2 | |||||
Exon 7 copy number | |||||
0 | 0 (0) | 0 (0) | 1 (4.2) | 0 (0) | 1 (1.6) |
1 | 2 (22.2) | 4 (30.8) | 11 (45.8) | 9 (56.3) | 26 (41.9) |
2 | 6 (66.7) | 8 (61.5) | 9 (37.5) | 7 (43.8) | 30 (48.4) |
3 | 1 (11.1) | 1 (7.7) | 2 (8.3) | 0 (0) | 4 (6.5) |
4 | 0 (0) | 0 (0) | 1 (4.2) | 0 (0) | 1 (1.6) |
Exon 8 copy number | |||||
0 | 0 (0) | 0 (0) | 1 (4.2) | 0 (0) | 1 (1.6) |
1 | 2 (22.2) | 4 (30.8) | 13 (54.2) | 10 (62.5) | 29 (46.8) |
2 | 6 (66.7) | 9 (69.2) | 9 (37.5) | 6 (37.5) | 30 (48.4) |
3 | 1 (11.1) | 0 (0) | 0 (0) | 0 (0) | 1 (1.6) |
4 | 0 (0) | 0 (0) | 1 (4.2) | 0 (0) | 1 (1.6) |