SCN5A Variant V1777M

Summary of observed carriers, functional annotations, and structural context for SCN5A V1777M. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT3 penetrance

29%

4/22 effective observations

Estimated BrS1 penetrance

5%

1/22 effective observations

Total carriers

12

0 BrS1 · 3 LQT3 · 9 unaffected

V1777M is present in 5 alleles in gnomAD. This residue resides in a Non_Hotspot region for Brugada syndrome and a 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 (%)
-2.7 1 -2.47 0.927 7 55

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
15840476 2005 1 1 0 0
25904541 2015 1 1 0 0
27566755 2016 2 2 0 0
11463728 2001 6 1 0 1 2:1 AV block
19716085 2009 1 1 0 0
30059973 2018 8 8 0 0
Literature, cohort, and gnomAD 12 9 3 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)
12085742 2002
15840476 2005
25904541 2015
27566755 2016
11463728 2001 HEK-tSA202 -8.99 -12.43 1320
19716085 2009
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 V1777M.
Neighbour residue Distance (Å) Observed variants
414 11 M414V,
1785 10
1778 4
1480 14 c.4437+5G>A, c.4438-1C>T,
1773 7
1653 11
1771 11 I1771T,
1652 8 M1652T, M1652R,
1777 0 V1777M, V1777L, V1777L,
1487 14 M1487L, M1487L, M1487K,
418 15 E418K,
409 15 L409V, L409P,
1650 12 L1650F,
1492 9
1656 15
417 14
1477 9 K1477N, K1477N,
1491 14 Q1491H, Q1491H,
1471 14
1779 6 T1779M,
1493 8 p.K1493del, K1493X, K1493R,
1470 13
1478 11 K1478E,
1776 4
1787 11 S1787N,
1786 12 c.5356_5357delCT, L1786Q, L1786R,
1648 10
1769 12
415 15 A415T,
1495 13 Y1495S,
1649 8 A1649V,
1774 6 N1774D, c.5321_5324dupACTT,
1473 13 F1473S, F1473C,
1496 9
1474 10
1481 12 G1481R, G1481R, G1481E, G1481V,
1781 5 E1781G, E1781D, E1781D,
1789 15
1772 10 L1772V,
1499 14
1645 11 T1645M,
1488 13 T1488R,
1784 12 E1784K, E1784X,
410 11 A410V,
1780 6 E1780G,
1788 12 c.5361_5364delTGAG,
1770 11 I1770V,
1651 13
1500 12 p.K1500del,
413 13 A413T, A413E,
1791 15
1482 13
407 14
1783 10
1476 15 Q1476X, Q1476R,
1775 7 F1775V, p.F1775LfsX15,
1642 14 G1642E,
1497 12
1490 12
1475 14 p.Q1475NfsX6, Q1475L,
1790 15 D1790N, D1790G, p.D1790del
1494 15
411 13 V411M,
1647 14
1646 11
1489 9 E1489D, E1489D,
1782 9