Table 1. KCNQ1 gene variants characterised in this study.
Representation of novel/recurrent KCNQ1 variants and phenotypic presentation of the index patients (refer to reference [15]): The patients presented with syncope, resuscitated sudden cardiac death (RSCD), or surviving parents of sudden cardiac death (SCD) in young children. All were subsequently identified as Romano-Ward Syndrome (RWS) patients by presentation of QT interval elongation and mutations in KCNQ1 (LQT1).
| Sequence Variants and Amino Acid Changes | Protein Position | Age (yrs) |
Gender | Ethnicity | Syncope | SCD of 1° Relative | RSCD | Identified trigger/s | QTc (ms) |
|---|---|---|---|---|---|---|---|---|---|
| 136G>A : A46T | N-terminal | 57 | F | European | Y | Y | Stress | 620 | |
| 794C>T : T265I | S5 | 40 | F | European | Y | Y | Rest / Sibutramine | 660 | |
| 887T>C : F296S | S5/pore | 14 | F | European | 490 | ||||
| 905C>T : A302V | Pore | 12 | F | Maori | Y | Exercise/stress | 490 | ||
| 947G>A : G316E | Pore | 8 | M | European | Y | Y* | Exercise (water) | 560 | |
| 1016T>C : F339S | S6 | 9 | M | European | Y | Y | Exercise | 480 | |
| 1078A>G : R360G | C-terminal | 15 | F | European | Y | Exercise (water) | 600 | ||
| 1363C>T : H445Y | C-terminal | 38 | F | European | Y | 470 | |||
| 1637C>T : S546L | C-terminal | 9 | M | European | Y | Exercise (water) | 480 |
Y* = DC cardioversion required