SCN5A Variant L1704H

Summary of observed carriers, functional annotations, and structural context for SCN5A L1704H. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT3 penetrance

1%

0/11 effective observations

Estimated BrS1 penetrance

18%

2/11 effective observations

Total carriers

1

0 BrS1 · 0 LQT3 · 1 unaffected

L1704H has not been reported in gnomAD. This residue resides in a Mild_Hotspot region for Brugada syndrome and a Non_Hotspot region for LQT3.

Variant features alone are equivalent to phenotyping 2 individuals for Brugada syndrome and 0 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 -6.08 0.99 17 1

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
26746457 2016 1 0 0 0
Literature, cohort, and gnomAD 1 1 0 0
Variant features alone 15 13 0 2

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)
26746457 2016

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 L1704H.
Neighbour residue Distance (Å) Observed variants
1702 7
387 14
1757 14
1715 13
1687 13
391 15
1698 10 A1698T,
1756 11 I1756V,
1673 11
1675 10
1764 13 c.5290delG, V1764F
1666 11
371 15 Q371E,
1711 10 c.5131delG,
1754 12
1707 5
1694 8
1704 0 L1704H,
1706 7 Q1706H, Q1706H,
1695 14 Q1695X,
1716 10 p.L1716SfsX71,
1714 15 D1714G,
1688 13
1669 10
1671 8
1668 5 M1668T,
1676 11 M1676T, M1676I, M1676I, M1676I,
1692 10
1753 14 T1753A,
1672 7 S1672Y,
1693 11
378 11
1699 9
1665 10
1712 11 G1712S, G1712C,
379 13
1703 5
1663 13
397 14 I397V, I397F, I397T,
1759 10 S1759C,
1719 15
1709 9 p.T1709del, T1709R, T1709M,
1701 6 M1701I, M1701I, M1701I,
1758 12 I1758V, p.I1758del,
1678 14 N1678S,
1223 14 c.3667delG,
1755 7
1697 11
393 14
1674 12 F1674V,
1713 10
390 11
394 12
1748 13 p.G1748del, G1748D,
1708 6 T1708I,
382 14
1696 12
374 12 W374G,
1705 5
1700 6
1717 13 L1717P,
1763 13 V1763M, V1763L, V1763L,
1751 9
1677 14
1760 13
1752 9
1670 10
1661 13 G1661R, G1661R, G1661E,
375 12
1691 13
1710 11 S1710L,
1720 14 c.5157delC,
1679 11
398 14
1667 9 V1667I,
1664 10