Table 2.
Copy numbers of SMA-related genes in 42 Chinese SMA patients determined by MLPA
| Total | Gene copy number | ||||||
|---|---|---|---|---|---|---|---|
| Pattern | Group | N = 42 | Normal SMN1 gene | Normal SMN2 gene | Normal NAIP gene | Hybrid SMN gene | Gene lacking partial sequences |
| A | 1 | 3(7.1%) | 0 | 2 | 1 | 0 | 0 |
| B | 2 | 3(7.1%) | 0 | 2 | 0 | 0 | 1a |
| C | 3 | 1(2.4%) | 0 | 1 | 0 | 1e | 1a |
| D | 4 | 1(2.4%) | 0 | 2 | 1 | 0 | 1a |
| E | 5 | 1(2.4%) | 0 | 3 | 1 | 0 | 1a |
| F | 6/7 | 5(11.9%) | 0 | 3 | 2 | 0 | 0 |
| G | 8 | 2(4.8%) | 0 | 4 | 2 | 0 | 0 |
| H | 9 | 1(2.4%) | 0 | 2 | 1 | 0 | 1a and 1b |
| I | 10 | 2(4.8%) | 0 | 2 | 2 | 0 | 1c |
| J | 11 | 9(21.3%) | 0 | 3 | 1 | 0 | 1a |
| K | 12 | 6(14.2%) | 0 | 3 | 1 | 0 | 0 |
| L | 13 | 1(2.4%) | 0 | 2 | 1 | 1e | 0 |
| M | 14 | 1(2.4%) | 0 | 1 | 1 | 1e | 0 |
| N | 15 | 1(2.4%) | 0 | 3 | 2 | 0 | 1d |
| O | 16 | 2(4.8%) | 0 | 3 | 1 | 0 | 1a and 1d |
| P | 17 | 2(4.8%) | 0 | 2 | 2 | 0 | 0 |
| Q | 18 | 1(2.4%) | 0 | 2 | 1 | 1f | 1a |
a:NAIP gene lacking exon 5, b:SMN1 gene lacking exon7, c:SMN2 gene lacking exon7, d:SMN2 gene lacking exon 1 to exon 7, e:Hybrid SMN gene in which exon 8 of SMN2 gene was converted to exon 8 of SMN1, f:Hybrid SMN gene in which exon 7 of SMN1 gene was converted to exon 7 of SMN2.