SCN5A Variant A1221V

Summary of observed carriers, functional annotations, and structural context for SCN5A A1221V. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT3 penetrance

24%

2/15 effective observations

Estimated BrS1 penetrance

10%

1/15 effective observations

Total carriers

5

0 BrS1 · 1 LQT3 · 4 unaffected

A1221V is present in 3 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 (%)
-3.69 0.945 -1.01 0.854 15 38

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
26669661 2016 2 1 0 0
30059973 2018 2 2 0 0
Literature, cohort, and gnomAD 5 4 1 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)
26669661 2016
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 A1221V.
Neighbour residue Distance (Å) Observed variants
1245 12 M1245I, M1245I, M1245I,
1218 5 S1218T, S1218I,
1304 12 T1304M,
1217 7
1243 11 D1243N,
1216 10 L1216V,
1234 12
1698 14 A1698T
1220 3 G1220E,
1673 10
1213 12
1241 12
1309 14 R1309C, R1309H,
1226 10
1669 11
1221 0 A1221V,
1242 9
1676 13 M1676T, M1676I, M1676I, M1676I,
1219 5 S1219N,
1672 13 S1672Y,
1239 6 L1239P,
1310 13
1306 10 R1306S, R1306H,
1665 15
1305 15
1246 10
1235 8
1237 12 V1237F,
1307 11
1228 13 Y1228H, Y1228C, Y1228F,
1223 5 c.3667delG,
1697 10
1222 4 p.L1222LfsX7, L1222R,
1227 14
1229 11
1215 11 I1215V,
1301 14
1214 12 M1214T,
1696 13
1677 15
1308 15 L1308F,
1224 5
1670 14
1240 11 E1240Q,
1225 7 E1225K, G1225K,
1238 9
1236 13 K1236R, K1236N, K1236N,
1303 10 R1303W, R1303Q,
1666 15