Table 2.
Classification according to the syndrome characteristics, based only on physical examination
| Chromosomal alteration | Classic syndrome | Undefined Syndrome | Heart disease + dysmorphism | Isolated heart disease | Total |
|---|---|---|---|---|---|
| +21 | 40 | 0 | 0 | 0 | 40 |
| +18 | 1 | 1 | 0 | 0 | 2 |
| XXX | 0 | 0 | 1 | 0 | 1 |
| 45,X | 1 | 0 | 0 | 0 | 1 |
| der(14;21),+21 | 2 | 0 | 0 | 0 | 2 |
| i(21q) | 1 | 0 | 0 | 0 | 1 |
| dup(17p) | 0 | 1 | 0 | 0 | 1 |
| del(6p) | 0 | 1 | 0 | 0 | 1 |
| add(18p) | 0 | 1 | 0 | 0 | 1 |
| Total | 44 | 5 | 1 | 0 | 50 |
+ 18: full trisomy of chromosome 18; +21: full trisomy of chromosome 21; add (18p): additional material by the end of the short arm of chromosome 18; 45,X: monosomy X, del (6p): deletion of the short arm of chromosome 6; der(14;21),+21: trisomy of chromosome 21 secondary to translocation between chromosomes 14 and 21; dup (17p): duplication of the short arm of chromosome 17; i(21q) Down syndrome secondary to isochromosome of the long arm of chromosome 21; XXX: trisomy X.