SCN5A Variant V253G Detail

We estimate the penetrance of LQTS for SCN5A V253G around 38% and the Brugada syndrome penetrance around 10%. SCN5A V253G was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. V253G is not present in gnomAD. V253G has been functionally characterized in 0 papers. This residue is located in a Non_Hotspot region for Brugada syndrome and a Hotspot region for LQTS. In silico predictions, functional data (if available), and location in structure are equivalent to phenotyping 10 individuals for Brugada syndrome (1 diagnosed with Brugada syndrome) and 5 individuals for LQTS (1 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A V253G around 38% (1/10) and the Brugada syndrome penetrance around 10% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.98 4 49
PROVEAN scores less than -2 are considered deleterious. REVEL scores higher than 0.5 or 0.75 are considered likely pathogenic (higher sensitivity with the former cutoff, higher specificity with the latter cutoff). A PolyPhen-2 score of 0.85 or greater is considered likely pathogenic. BLAST-PSSM reflects the evolutionary conservation of residue substitutions, more negative numbers indicate fewer observations of the specific substitution than is expected. Penetrance Density is our previously published method to calculate the average BrS/LQTS probability density in a shell of residues surrounding a residue of interest (Kroncke et al. 2019).

Reported Carrier Data

PubMed ID Year Carriers Unaffected LQT3 BrS1 Other Other Disease
LITERATURE, COHORT, AND GNOMAD: - 0 0 0 0 -
VARIANT FEATURES ALONE: - 15 13 1 1 - -
Summary totals might not agree with the literature table because of duplicate patients, which were excluded from the total counts. We do not distinguish here between multiple missense codons. Missense variants are combined across degenerate codon substitutions since codon-level data were not consistently available for curation.

V253G has 58 previously observed neighbors within 15 angstroms

A residue within a folded protein on average has nearest neighbors that fall roughly into two shells: a "nearest" neighbor around 5-6 angstroms and a second shell around 11 angstroms. All variants shown in the rightmost column have been observed in at least one individual in the literature or gnomAD.

Neighbor Distance (Angstroms) Variants Observed in Individuals
403 12
414 12 M414V,
1643 7 I1643L,
404 8 L404Q, L404V,
249 9 K249X,
247 10 V247L,
254 4
1771 13 I1771T,
401 13 S401P,
1634 14 L1634P,
250 5
409 12 L409P, L409V,
928 11 L928P,
925 15 I925F,
1650 11 L1650F,
260 10
366 14
1641 14
258 9 V258A,
1639 14 G1639A,
246 11
1779 14 T1779M,
412 12 V412D,
924 12 V924I,
245 13 Q245K,
369 12 M369K,
415 14 A415T,
1649 13 A1649V,
1644 13 R1644C, R1644L, R1644H,
1640 11
262 14 S262G,
256 5
405 11
248 12
261 12
255 6
1772 14 L1772V,
1645 12 T1645M,
251 5
410 10 A410V,
929 13
259 11
1633 15
413 14 A413T, A413E,
1637 13
408 7
253 0
407 7
1775 11 p.F1775LfsX15, F1775V,
1642 9 G1642E,
406 12 N406S, N406K,
252 5
411 8 V411M,
932 14
1647 10
257 6
400 12 G400R, G400E, G400A,
1646 8