Table 1 Demographics of patients with neurodevelopmental delay/intellectual disability
Category | Number of patients (%) |
|---|---|
Sex (male: female) | 585 (54.9): 480 (45.1) |
Onset at presentation | |
 Antenatal | 10 (0.9%) |
 Neonatal (from birth to 4 months) | 628 (58.9%) |
 Infant (from more than 4 months to1 year) | 273 (25.6%) |
 Early childhood (from more than1 year to 5 years) | 65 (6.1%) |
 Childhood (from more than 5 years to 12 years) | 77 (7.2%) |
 Adolescent (from more than 12 years to 18 years) | 10 (0.9%) |
 Adult | 3 (0.3%) |
Average number of human phenotype ontology (HPO) terms | 8.6 ± 4.6 |
Organ involvement | |
 Nervous system | 1065 (100%) |
 Musculoskeletal and limb system | 767 (71.9%) |
 Head or neck, including facial dysmorphism | 616 (57.8%) |
 Growth | 342 (32.1%) |
 Eye system | 286 (26.8%) |
 Ear system | 230 (21.6%) |
 Cardiovascular system | 200 (18.8%) |
 Endocrine and metabolism/homeostasis system | 185 (17.4%) |
 Skin | 181 (17.0%) |
 Abnormality of prenatal development or birth | 167 (15.7%) |
 Genitourinary system | 146 (13.7%) |
 Gastrointestinal system | 106 (9.9%) |
 Connective tissue system | 72 (6.7%) |
 Blood and immune system | 50 (4.7%) |
 Respiratory system | 35 (3.3%) |
 Neoplasm | 22 (2.1%) |
Age at whole exome sequencing | 6.5 year (min 0–max 47, SD 8.1) |
Total number of patients with previous genetic testing | 645 (60.6) |
 Single gene test | 153 (14.4) |
 Panel test | 13 (1.2) |
 Targeted exome sequencing | 20 (1.9) |
 Chromosome analysis or fluorescence in situ hybridization | 355 (33.3) |
 Microarray | 284 (26.6) |
 Multiplex ligation-dependent probe amplification | 103 (9.7) |
 Mitochondrial full genome sequencing analysis | 26 (2.4) |