Clinical features in patients with Silver–Russell syndrome with hypomethylation of the imprinting control region (ICR) 1 and maternal uniparental disomy of chromosome 7 (mUPD7)
| ICR1 hypomethylation (n=44) | mUPD7 (n=20) | p Value | |
| Epidemiology | |||
| Male sex (%) | 50 | 25 | 0.10 |
| Age (years) (median (IQR)) | 3.6 (1.8, 8.4) | 6.4 (3.6, 10.1) | 0.08 |
| Maternal age (years) (mean (SD)) | 30.4 (4.6) | 33.8 (6.3) | 0.02 |
| Paternal age (years) (mean (SD)) | 33.6 (5.9) | 36.3 (6.9) | 0.13 |
| Pregnancy | |||
| History of infertility (%) | 18 | 20 | 1.00 |
| Assisted reproductive technology (%) | 11 | 0 | 0.31 |
| Placental abnormality (%) | 35 | 8 | 0.08 |
| Growth | |||
| Birth weight ≤−2 SD (%) | 82 | 70 | 0.34 |
| Height at examination ≤−2 SD (%) | 57 | 65 | 0.59 |
| Relative macrocephaly (%)* | 70 | 90 | 0.12 |
| Asymmetry (%) | 68 | 30 | 0.006 |
| Face (%) | 48 | 15 | 0.01 |
| Limbs (%) | 34 | 10 | 0.07 |
| Development | |||
| Global delay (%) | 20 | 65 | 0.001 |
| Mild (%) | 11 | 55 | |
| Moderate (%) | 2 | 10 | |
| Delayed motor milestones (%) | 26 (n=34)† | 7 (n=14)† | 0.66 |
| Speech delay (%) | 39 | 50 | 0.43 |
| Speech therapy (if ≥2.5 years) (%) | 32 (n=28) | 67 (n=18) | 0.03 |
| Statement of education (if ≥3.5 years) (%) | 9 (n=23) | 25 (n=16) | 0.21 |
| Behavioural problems (%) | 9 | 20 | 0.24 |
| Congenital abnormalities (%) | 36 | 10 | 0.04 |
| Cleft palate/bifid uvula (%) | 7 | 0 | 0.55 |
| Congenital heart defect (%) | 9 | 0 | 0.30 |
| Male genital anomaly (%) | 23 (n=22) | 0 (n=5) | 0.55 |
| Renal anomaly (%) | 0 | 10 | 0.09 |
| Scoliosis (%) | 9 | 5 | 1.00 |
| Other skeletal abnormality (%) | 9 | 0 | 0.30 |
| Other problems | |||
| Excessive sweating (%) | 64 | 75 | 0.41 |
| Hypoglycaemia (%) | 24 (n=37) | 29 (n=17) | 0.75 |
| Feeding difficulties (%) | 84 | 90 | 0.71 |
| Gastro-oesophageal reflux (%) | 14 | 10 | 1.00 |
| Otitis media (%) | 14 | 20 | 0.71 |
| Delayed closure of fontanelles (%) | 43 (n=28) | 36 (n=11) | 1.00 |
| Movement disorder (%) | 0 | 15 | 0.03 |
| Craniofacial features | |||
| Triangular face (%) | 59 | 90 | 0.02 |
| Frontal bossing (%) | 60 | 60 | 1.00 |
| Micro/retrognathia (%) | 64 | 35 | 0.06 |
| Irregular/crowded teeth (%) | 36 | 45 | 0.59 |
| Small teeth (%) | 11 | 20 | 0.44 |
| Down-turned corners of mouth (%) | 30 | 20 | 0.55 |
| Thin upper lip (%) | 27 | 30 | 1.00 |
| Low-set/posteriorly rotated ears (%) | 36 | 75 | 0.007 |
| Other clinical signs | |||
| 5th finger clinodactyly (%) | 75 | 45 | 0.03 |
| 2/3 toe syndactyly (%) | 23 | 20 | 1.00 |
| Camptodactyly (%) | 16 | 25 | 0.49 |
| Joint contractures (%) | 11 | 0 | 0.31 |
| Café au lait patches (%) | 14 | 15 | 1.00 |