Table 2. The summary of 23 dead SYS cases.
| Ref | Gender | Age of death | Cause of death | Variant | Inheritance | Gestational age | Decreased fetal movement | Respiratory distress | Intubation/ventilation | Hypotonia | Feeding problems | Cardiovascular anomalies | Joint contractures | Facial deformity | Genital anomalies |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| This study | F | 2 m | Respiratory failure | c.1912C>T | Paternal | 39 w | + | + | + | + | + | ASD, PDA, PH | + | − | + |
| F | 1 m | Respiratory failure | c.1996dupC | Paternal | NA | NA | + | + | + | + | ASD, PDA, PH | + | + | + | |
| F | 1 m | Respiratory failure | c.1996dupC | De novo | NA | NA | + | + | + | + | ASD, VSD, PDA | + | + | + | |
| M | 7 d | Hemophagocytic syndrome | c.3583delA | NA | 39 w | NA | − | − | − | + | ASD, PFO, PDA, PH | − | − | + | |
| Chen X | F | 20 d | Respiratory failure | c.1996dupC | De novo | 40 w | + | + | + | + | + | VSD, ASD, PH | + | + | − |
| F | 98 d | Respiratory failure | c.1996dupC | De novo | 40 w | − | + | + | + | + | VSD, PFO | + | + | − | |
| Xiao B | M | 7 d | Respiratory failure | c.1996dupC | Paternal | 36 w | NA | + | + | + | + | NA | + | + | + |
| M | 15 d | Respiratory failure | c.1996dupC | Paternal | 36 w | NA | + | + | + | + | NA | + | − | + | |
| F | 110 d | Apnea | c.1996dupC | Paternal | 40 w | NA | + | + | − | + | NA | + | + | NA | |
| M | 7 d | Respiratory failure | c.1996dupC | Paternal | 31 w | NA | + | + | + | + | NA | + | + | + | |
| F | 8 d | Respiratory failure | c.1996dupC | Paternal | 39 w | NA | + | + | + | + | NA | + | + | NA | |
| McCarthy* | F | 8 y | NA | c.1996dupC | Paternal | NA | − | NA | NA | + | + | NA | + | + | − |
| Guo | M | 35 g.w. | NA | c.1996delC | Paternal | 35 w | + | NA | NA | + | + | − | + | + | + |
| Kleinendorst | F | 23 m | Obesity/sleep apnea | c.1850G>A | De novo | 40 w | + | + | NA | + | + | NA | + | + | NA |
| Tong | F | 11 m | Cardiovascular failure | c.1628delC | Paternal | 40 w | + | + | + | + | + | NA | + | + | − |
| F | 2 m | NA | c.1996dupC | De novo | 37 w + 4 d | NA | + | + | + | + | NA | + | + | + | |
| Fountain | F | 21 g.w. | Fetal akinesia | c.1996delC | Paternal | 21 w + 4 d | + | NA | NA | NA | NA. | − | + | + | − |
| M | 14 g.w. | Fetal akinesia | c.1996delC | Paternal | 14 w + 6 d | + | NA | NA | NA | NA | − | + | + | − | |
| M | 9 m | Suspected apnea | c.1996dupC | Paternal | NA | NA | NA | NA | NA | + | NA. | + | + | + | |
| Mejlachowicz | F | 24 g.w. | Fetal akinesia | c.1996delC | Paternal | 24 w | + | \ | \ | \ | \ | \ | \ | \ | \ |
| F | 24 g.w. | Fetal akinesia | c.1996delC | Paternal | 24 w | + | \ | \ | \ | \ | \ | \ | \ | \ | |
| M | 27 g.w. | Fetal akinesia | c.1996delC | Paternal | 27 w | + | \ | \ | \ | \ | \ | \ | \ | \ | |
| F | 2 d | Respiratory distress | c.2118delT | De novo | NA | + | + | + | + | + | NA | + | + | NA |
*, this patient of McCarthy’s study had been reported previously as patient 2 by Fountain et al. in 2016. F, female; M, male; g.w., gestational age; NA, not available; ASD, atrial septal defect; PDA, patent ductus arteriosus; PH, pulmonary hypertension; PFO, patent foramen ovale; VSD, ventricular septal defect.