Demographics, history, investigations, cardiac testing and final diagnosis in 5 cases in which testing showed genetic variants in LQTS genes outside the prospective study period (‘selected’)
| ID | Age | Ancestry | Circumstances of death | Sleeping arrangement | Sleep position | SIDS category | Previous medical history | Cardiac tests during life | Family history of syncope or SIDS | Social history | No. of family members investigated | Positive heart tests | Genetic variant | Final cardiac diagnosis |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 1 year | Asian | Found deceased in bed | Own bed | Found prone | SIDS II | Nil. Full term. | Nil | No | No adverse social factors | 3 | No | R1193Q in SCN5A | Unlikely LQTS |
| 2 | <1 month | Pacific | Found deceased in bed | co-sleeping | Found prone | SIDS II | Nil. Full term. | Nil | No | Unknown | 0 | – | I759F in SCN5A | Uncertain Possible LQT3 |
| 5 | 3 month | Maori | Seizures then unresponsive. | Not stated | Not stated | n/a | Unknown | Nil | Unknown | Unknown | 0 | – | R1047L in KCNH2 and R1193Q in SCN5A | Uncertain Possible LQT2 |
| 7 | 7 month | NZ European | Found deceased in bed | Not stated | Not stated | SIDS IB | Unknown | No | Yes* | Unknown | 9 | Equivocal QT prolongation. | E146K in KCNQ1 | Possible LQT1 |
| 8 | <1 month | NZ European | Cardiac arrest while feeding. | n/a | n/a | n/a | Nil. Full term. | QTc prolonged postarrest | No | No adverse social factors | 5 | No-Normal ECGs | F1522Y in SCN5A and H558R in SCN5A | Possible LQT |
*Retrospective LQTS testing done after 2-year-old sibling found to be gene positive after sudden death.
LQTS, long QT syndrome; SIDS, sudden infant death syndrome.