SCN5A Variant I1643L

Summary of observed carriers, functional annotations, and structural context for SCN5A I1643L. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT3 penetrance

11%

0/11 effective observations

Estimated BrS1 penetrance

14%

1/11 effective observations

Total carriers

1

0 BrS1 · 0 LQT3 · 1 unaffected

I1643L is present in 1 alleles in gnomAD. This residue resides in a Mild_Hotspot region for Brugada syndrome and a Mild_Hotspot region for LQT3.

Variant features alone are equivalent to phenotyping 1 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 (%)
-1.85 0.943 3.55 0.915 20 14

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
Literature, cohort, and gnomAD 1 1 0 0
Variant features alone 15 14 0 1

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

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 I1643L.
Neighbour residue Distance (Å) Observed variants
403 14
414 14 M414V,
1643 0 I1643L,
404 12 L404V, L404Q,
1778 12
249 11 K249X,
1635 14
254 10
1771 14 I1771T,
1652 14 M1652T, M1652R,
1634 9 L1634P,
250 10
1650 10 L1650F,
260 12
1641 8
258 12 V258A,
1639 9 G1639A,
1779 12 T1779M,
1787 14 S1787N,
1648 10
1649 10 A1649V,
1774 15 N1774D, c.5321_5324dupACTT,
1644 7 R1644C, R1644H, R1644L,
1640 6
256 7
248 15
1789 12
255 8
1645 6 T1645M,
251 9
410 13 A410V,
1788 15 c.5361_5364delTGAG
1638 11 R1638X, R1638Q,
1651 12
259 11
1633 11
1637 6
408 13
253 7
1636 11
407 10
1775 11 F1775V, p.F1775LfsX15,
1642 4 G1642E,
1631 14 G1631D,
252 6
411 12 V411M,
1647 5
257 10
1646 5
1782 13