Clinical features of patients with a CHD7 mutation compared to clinically diagnosed patients with CHARGE syndrome
| Feature | Our CHD7 positive cohort (n=280) | CHD7 positive cohort from the literature (n=254)* | CHARGE patients before CHD7 discovery (n=124)† |
| External ear anomaly | 224/231‡ | 214/235 | 74/77 |
| 97% (80–98%)§ | 91% | 96% | |
| Cranial nerve dysfunction (VII, VIII and others) | 173/174 | ? | 107/124 |
| 99% (62–100%) | 86% | ||
| Semicircular canal anomaly | 110/117 | 94/96 | 12/12 |
| 94% (39–98%) | 98% | 100% | |
| Coloboma | 189/234 | 190/253 | 96/124 |
| 81% (68–84%) | 75% | 77% | |
| Choanal atresia | 99/179 | 95/247 | 76/124 |
| 55% (35–71%) | 38% | 61% | |
| Cleft lip and/or palate | 79/163 | 79/242 | 22/124 |
| 48% (28–70%) | 33% | 18%¶ | |
| Feeding difficulties necessitating tube feeding | 90/110 | ? | 40/47 |
| 82% (32–93%) | 85% | ||
| Facial palsy | 80/121 | 72/187 | 17/47 |
| 66% (29–85%) | 39% | 36% | |
| Anosmia on formal smell testing | 24/30 | ? | ? |
| 80% | |||
| Genital hypoplasia | 118/145 | 116/187 | 45/124 |
| 81% (42–90%) | 62% | 36%¶ | |
| Congenital heart defect | 191/252 | 193/250 | 105/124 |
| 76% (68–78%) | 77% | 85%¶ | |
| Tracheo-oesophageal anomaly | 42/146 | 35/185 | 22/124 |
| 29% (15–63%) | 19% | 18% | |
| Developmental delay | Delayed motor milestones 147/149 99% (53–99%) Intellectual disability 108/134 74% (39–91%) | Developmental delay 107/141 76% | Developmental delay 47/47 100% |
| Growth retardation | 35/94 | 101/141 | 80/124 |
| 37% (13–79%) | 72% | 65% |
↵* CHD7 positive cohort from the literature as reviewed by Zentner et al in 2010.24 This cohort partially overlaps with our CHD7 positive cohort because the phenotypes of 64 of our patients were published previously.20 26 35–40
↵† Cohort of patients with clinically diagnosed CHARGE syndrome reported by Tellier et al in 1998 and Issekutz et al in 2005, before CHD7 analysis was possible.7 34
↵‡ Frequencies are represented as the number of patients with a particular feature/the total number of patients that were tested for that particular feature.
↵§ The range of percentages presented between brackets was calculated as: (positive/total)×100%−(positive+unknown/total)×100% (for further explanation see text).
↵¶ Outside the frequency range of patients with a CHD7 mutation.