SCN5A Variant G1748D

Summary of observed carriers, functional annotations, and structural context for SCN5A G1748D. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT3 penetrance

28%

1/11 effective observations

Estimated BrS1 penetrance

38%

4/11 effective observations

Total carriers

1

1 BrS1 · 0 LQT3 · 0 unaffected

G1748D has not been reported in gnomAD. This residue resides in a Mild_Hotspot region for Brugada syndrome and a Hotspot region for LQT3.

Variant features alone are equivalent to phenotyping 3 individuals for Brugada syndrome and 1 individuals for LQT3.

In silico predictors

Variant-level computational predictors.
PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-6.48 1 -3.51 0.982 34 44

PROVEAN scores below -2 suggest deleterious impact. REVEL scores above 0.5–0.75 are often interpreted as likely pathogenic. PolyPhen-2 scores above 0.85 are typically pathogenic. Penetrance density summarises neighbouring residue risk (Kroncke et al. 2019).

Reported carrier data

Observed carriers by publication or cohort.
Source Year Carriers Unaffected LQT3 BrS1 Other Other Disease
23085483 2013 1 0 1 0
Literature, cohort, and gnomAD 1 0 0 1
Variant features alone 15 11 1 3

Totals may differ from individual publications due to duplicate patients removed during curation.

Functional data

Peak and late/persistent current values are relative to wild-type (100% indicates no change). V1/2 activation and inactivation denote the membrane potentials (mV) at which half-maximal current is achieved.

Published electrophysiology measurements.
PubMed ID Year Cell Type Peak Current (% WT) V1/2 Activation (mV) V1/2 Inactivation (mV) Late/Persistent Current (% WT)
23085483 2013 CHO 10 13.4 13.8
30232268 2018 CHO 13

Nearby variants

Neighbouring residues within 15 Ångström provide structural context. Variants listed in the right-most column have been observed clinically or in gnomAD.

Previously observed variants near G1748D.
Neighbour residue Distance (Å) Observed variants
1746 5 A1746T, A1746V,
1724 15
1406 13 G1406R, G1406R, G1406E,
1757 14
1715 12
1687 15
1745 6
1756 11 I1756V,
1675 10
1743 9 G1743R, G1743R, G1743E,
1723 13 T1723N,
1754 9
1707 12
1694 11
1411 14
1407 14
1704 13 L1704H,
1410 10
1747 4 V1747M,
1716 10 p.L1716SfsX71,
1714 12 D1714G,
1688 14
1671 11
1676 14 M1676T, M1676I, M1676I, M1676I,
1744 6 S1744I,
1721 6
1753 7 T1753A,
1672 14 S1672Y,
1742 13
1712 14 G1712S, G1712C,
1680 13 A1680T, A1680P,
1703 14
1719 10
1758 15 I1758V, p.I1758del
1678 9 N1678S,
1755 11
1674 10 F1674V,
1399 14
1713 11
1748 0 p.G1748del, G1748D,
1683 15
1409 14 Y1409C, Y1409X,
1400 14 V1400I,
1718 10 S1718R, S1718R, S1718R,
1700 15
1717 7 L1717P,
1751 5
1677 12
1682 12
1750 5 L1750F,
1752 5
1722 10 N1722D,
1749 4 I1749N,
1720 6 c.5157delC,
1679 8
1685 14
1414 13 Q1414H, Q1414H,
1413 13