SCN5A Variant T1645M

Summary of observed carriers, functional annotations, and structural context for SCN5A T1645M. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT3 penetrance

26%

3/18 effective observations

Estimated BrS1 penetrance

8%

1/18 effective observations

Total carriers

8

0 BrS1 · 2 LQT3 · 6 unaffected

T1645M is present in 6 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 1 individuals for LQT3.

In silico predictors

Variant-level computational predictors.
PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-5.59 1 2.95 0.948 14 27

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
10508990 1999 1 1 0 0
10973849 2000 1 1 0 0
29325976 2018 2 0 2 0
Literature, cohort, and gnomAD 8 6 2 0
Variant features alone 15 13 1 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)
10508990 1999
10973849 2000
29325976 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 T1645M.
Neighbour residue Distance (Å) Observed variants
403 15
414 12 M414V,
1785 12
1643 6 I1643L,
1778 7
249 13 K249X,
1653 13
1635 15
1771 13 I1771T,
1652 10 M1652T, M1652R,
1634 12 L1634P,
1824 15 P1824A
1777 11 V1777M, V1777L, V1777L,
250 14
1650 9 L1650F,
1641 6
1639 10 G1639A,
1779 8 T1779M,
1776 11
1787 8 S1787N,
1654 15
1786 12 c.5356_5357delCT, L1786Q, L1786R,
1648 6
1649 7 A1649V,
1774 11 N1774D, c.5321_5324dupACTT,
1644 5 R1644C, R1644H, R1644L,
1640 8
256 12
1793 13 M1793K,
1781 10 E1781G, E1781D, E1781D,
1789 8
255 14
1772 15 L1772V,
1645 0 T1645M,
251 14
410 13 A410V,
1780 12 E1780G,
1788 9 c.5361_5364delTGAG,
1638 11 R1638X, R1638Q,
1651 10
1500 14 p.K1500del,
1633 15
1791 13
1637 9
253 12
1792 12 D1792N, D1792Y, D1792V,
1636 14
407 12
1783 12
1775 8 F1775V, p.F1775LfsX15,
1642 5 G1642E,
1790 10 D1790N, D1790G, p.D1790del,
252 11
411 12 V411M,
1647 6
1822 15 c.5464_5467delTCTG, c.5464-5467delTCTG,
1646 5
1782 8