"Variants in genes encoding the calcium channels including CACNA1C (Cav1.2), CACNB2b (Cavβ2b) and CACNA2D1 (Cavα2δ) have been reported in up to 13% of probands. xref – xref Mutations in glycerol-3-phophate dehydrogenase 1-like enzyme gene ( GPD1L ), SCN1B (β 1 -subunit of Na channel), KCNE3 (MiRP2), SCN3B (β3-subunit of Na channel), KCNJ8 (Kir 6.1), KCND3 (Kv4.3), RANGRF (MOG1), SLMAP , ABCC9 (SUR2A), (Navβ2), PKP2 (Plakophillin-2), FGF12 (FHAF1), HEY 2, SEMA3A (Semaphorin) and KCNAB2 (Kvβ2) are relatively rare. xref – xref An association of BrS with SCN10A , a gene encoding a neuronal Na channel, was reported in 2014. xref , xref , xref There is controversy as to the pathogenicity of many SCN10A mutation with yields ranging between 5% and 16.7%. xref – xref Mutations in all of these genes lead to loss of function in sodium (I Na ) and calcium (ICa) channel currents, as well as to a gain of function in transient outward potassium current (I to ) or ATP-sensitive potassium current (IK-ATP). xref , xref "
"Recently, genome-wide association studies identified SCN10A , the gene encoding Na v 1.8, as a determinant of cardiac conduction parameters, and mutations in SCN10A have been associated with BrS."
"For example, the Na v 1.8 blocker A-803467 shortened action potentials in cardiomyocytes, and PR intervals were shorter in Scn10a − / − mice, suggesting that Na v 1.8 acts to lengthen cardiac conduction. xref , xref However, in mice treated with A-803467, QRS and PR were longer, and mutations in SCN10A were associated with BrS, suggesting acceleration of impulse propagation by Na v 1.8. xref , xref It is possible that numerous factors have to be considered in future experiments to solve this fascinating puzzle, like a possible alternative splicing in the heart, a species-dependent regulation of expression, the turn-over of the protein, a possible inducible expression under certain conditions, the cell-specificity of expression in different cardiac cells of higher mammals, essential interactions of Na v 1.8 with other cardiac proteins, or the role of SCN10A /Na v 1.8 in the diseased myocardium using animal models."
"To date more than 300 BrS-related mutations in SCN5A have been described xref , xref , xref Mutations in CACNA1C (Cav1.2), CACNB2b (Cavß2b) and CACNA2D1 (Cavα2δ) are found in approximately 13% of probands. xref - xref Mutations in glycerol-3-phophate dehydrogenase 1-like enzyme gene ( GPD1L ), SCN1B (β 1 -subunit of Na channel), KCNE3 (MiRP2), SCN3B (β3-subunit of Na channel), KCNJ8 (Kir 6.1), KCND3 (Kv4.3), RANGRF (MOG1), SLMAP , ABCC9 (SUR2A), (Navß2), PKP2 (Plakophillin-2), FGF12 (FHAF1), HEY 2, and SEMA3A (Semaphorin) are more rare. xref - xref xref - xref xref , xref - xref We recently reported an association of BrS with SCN10A , a neuronal sodium channel that co-associates with SCN5A , with a yield of 16.7%. xref Mutations in these genes lead to loss of function in sodium channel current (I Na ) and calcium channel current (I Ca ), as well as to a gain of function in transient outward potassium current (I to ) or ATP-sensitive potassium current (I K-ATP )."