SCN5A Variant I1749N

Summary of observed carriers, functional annotations, and structural context for SCN5A I1749N. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT3 penetrance

53%

3/11 effective observations

Estimated BrS1 penetrance

16%

1/11 effective observations

Total carriers

1

0 BrS1 · 1 LQT3 · 0 unaffected

I1749N 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 1 individuals for Brugada syndrome and 2 individuals for LQT3.

In silico predictors

Variant-level computational predictors.
PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-6.47 1 -4.36 0.959 14 59

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
30059973 2018 1 1 0 0
Literature, cohort, and gnomAD 1 0 1 0
Variant features alone 15 12 2 1

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)
30059973 2018

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 I1749N.
Neighbour residue Distance (Å) Observed variants
1746 5 A1746T, A1746V,
1724 14
1417 15
1406 10 G1406R, G1406R, G1406E,
1757 13
1715 13
1745 6
1756 11 I1756V,
1675 13
1743 12 G1743R, G1743R, G1743E,
1723 12 T1723N,
1754 9
1707 14
1694 15
1411 12
1407 10
1410 7
1747 6 V1747M,
1716 12 p.L1716SfsX71,
1714 12 D1714G,
1671 13
1404 13
1744 8 S1744I,
1721 7
1753 6 T1753A,
1712 15 G1712S, G1712C,
1412 14 L1412F,
1719 12
1408 12 G1408R, G1408R,
1758 15 I1758V, p.I1758del
1678 12 N1678S,
1755 12
1401 14
1674 13 F1674V,
1399 13
1713 11
1748 4 p.G1748del, G1748D,
1405 14 V1405M, V1405L, V1405L,
1409 10 Y1409C, Y1409X,
1400 13 V1400I,
1718 11 S1718R, S1718R, S1718R,
1717 8 L1717P,
1751 8
1682 15
1750 5 L1750F,
1752 7
1722 10 N1722D,
1749 0 I1749N,
1720 9 c.5157delC,
1679 12
1414 12 Q1414H, Q1414H,
1413 11