Table 1.
Clinical characteristics of the cohort
| Phenotypic characteristic | Number* | % Mutation positive | % Genetic component† |
| Total | 202 | 11 | 32 |
| Number of limbs affected | |||
| 4 | 20 | 30 | 55 |
| 3 | 6 | 33 | 50 |
| 2 | 72 | 17 | 44 |
| 1 | 104 | 2 | 17 |
| Bilateral malformation | 97 | 22 | 47 |
| Positive family history | 51 | 24 | 100 |
| Syndrome or association | 13 | 38 | 54 |
| Other non-limb malformations not classified into a syndrome | 14 | 36 | 43 |
| Polydactyly | |||
| Postaxial | 75 | 5 | 39 |
| Preaxial | 34 | 26 | 38 |
| Pre- and postaxial | 4 | 50 | 50 |
| Triphalangeal thumb | 5 | 80 | 80 |
| Syndactyly | 31 | 16 | 32 |
| Polysyndactyly | 12 | 33 | 42 |
| Longitudinal dysplasia | |||
| Radial | 8 | 25 | 63 |
| Ulnar | 3 | 0 | 0 |
| Central | 7 | 0 | 14 |
| Symbrachydactyly | 13 | 0 | 0 |
| Brachydactyly | 1 | 0 | 100 |
| Clinodactyly | 8 | 13 | 25 |
| Camptodactyly | 4 | 25 | 25 |
| Hypoplastic digits | |||
| Thumb | 4 | 0 | 0 |
| Other digits | 4 | 0 | 0 |
| Trigger thumb | 5 | 0 | 0 |
| Constriction ring syndrome | 3 | 0 | 0 |
| Other | 10 | 30 | 30 |
*Totals do not add up to 202 as 24 children had multiple limb malformations which were included in between two and five categories.
†Genetic component consists of individuals with either a cytogenetic or molecularly proven diagnosis, a positive family history of congenital limb malformation (CLM), or a known genetically determined syndrome (see section: Estimation of the overall genetic contribution to CLM).