SCN5A Variant T423N

Summary of observed carriers, functional annotations, and structural context for SCN5A T423N. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT3 penetrance

18%

0/10 effective observations

Estimated BrS1 penetrance

0/10 effective observations

Total carriers

0 BrS1 · 0 LQT3 · 0 unaffected

T423N has not been reported in gnomAD. This residue resides in a Non_Hotspot region for Brugada syndrome and a Mild_Hotspot region for LQT3.

Variant features alone are equivalent to phenotyping 0 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 (%)
NA	NA	NA	0.7	4	22

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	–	0	0	0	0		–
Variant features alone	–	15	15	0	0	–	–

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 T423N.
Neighbour residue	Distance (Å)	Observed variants
937	14
240	13	V240M,
418	9	E418K,
237	9
234	14	P234S,
417	10
245	14	Q245K,
415	12	A415T,
940	13	S940N
420	6
241	11
235	10	c.703+1G>A, G235R, G235R, c.704-1G>C,
419	6	Q419X,
423	0
837	14
239	12	I239V, I239V ,
242	12	A242D,
416	10	Y416C,
841	14	p.N841TfsX2, N841K, N841K,
236	12
238	7
838	13
422	4
421	7