Table 3.
Molecular Basis of Cardiac Channelopathies
| Gene | Locus | Protein | Frequency |
|---|---|---|---|
| Long QT Syndrome (LQTS) | |||
| KCNQ1 (LQT1)* | 11p15.5 | Kv7.1 | 30–35% |
| KCNH2 (LQT2)* | 7q35-36 | Kv11.1 | 25–30% |
| SCN5A (LQT3)* | 3p21-p24 | NaV1.5 | 5–10% |
| AKAP9* (LQT11) | 7q21-q22 | Yotiao | Rare |
| ANKB* (LQT4) | 4q25-q27 | Ankyrin B | Rare |
| CACNA1C* (LQT8) | 12p13.3 | L-type calcium channel | Rare |
| CAV3* (LQT9) | 3p25 | Caveolin 3 | Rare |
| KCNE1* (LQT5) | 21q22.1 | MinK | Rare |
| KCNE2* (LQT6) | 21q22.1 | MiRP1 | Rare |
| KCNJ2* (LQT7 and ATS1) | 17q23 | Kir2.1 | Rare |
| KCNJ5 (LQT13) | 11q23.3 | Kir3.4 | Rare |
| SCN4B* (LQT10) | 11q23.3 | Sodium channel β 4 subunit | Rare |
| SNTA1* (LQT12) | 20q11.2 | Syntrophin α 1 | Rare |
| Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) | |||
| RYR2 (CPVT1)* | 1q42.1-q43 | Ryanodine receptor 2 | 50–60% |
| KCNJ2 (CPVT3)* | 17q23 | Kir2.1 | 10% |
| CASQ2* (CPVT2) | 1p13.3-p11 | Calsequestrin 2 | 1–2% |
| Brugada Syndrome (BrS) | |||
| SCN5A (BrS1)* | 3p21-p24 | NaV1.5 | 20–30% |
| CACNA1C* (BrS3) | 2p13.3 | L-type calcium channel | Rare |
| CACNB2* (BrS4) | 10p12 | L-type calcium channel β 2 subunit | Rare |
| GPD1L* (BrS2) | 3p22.3 | Glycerol-3-phosphate dehydrogenase 1-like | Rare |
| KCNE3* (BrS6) | 11q13.4 | MiRP2 | Rare |
| KCNJ8 (BrS8) | 12p12.1 | Kir6.1 | Rare |
| SCN1B* (BrS5) | 19q13.1 | Sodium channel β 1 subunit | Rare |
| SCN3B (BrS7) | 11q24.1 | Sodium channel β 3 subunit | Rare |
*
Genes available as a commercially available genetic test.
Rare is defined as < 1% anticipated contribution to the syndrome.
Note that the rare disease-susceptibility genes are indicated in alphabetical order.
Although the disease genotypic subtype is provided in parentheses for these rare disease susceptibility genes, we recommend annotating only the common genotypes with such a numerical designation and refer to the rare ones with their gene descriptor such as AKAP9-LQTS rather than LQT11 and GPD1L-BrS rather than BrS2.