SCN5A Variant S262G Detail

We estimate the penetrance of LQTS for SCN5A S262G around 4% and the Brugada syndrome penetrance around 7%. SCN5A S262G was found in a total of 1 carriers in 1 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. S262G is present in 1 alleles in gnomAD. S262G has been functionally characterized in 1 papers. This residue is located in a Non_Hotspot region for Brugada syndrome and a Non_Hotspot region for LQTS. In silico predictions, functional data (if available), and location in structure are equivalent to phenotyping 10 individuals for Brugada syndrome (0 diagnosed with Brugada syndrome) and 5 individuals for LQTS (0 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A S262G around 4% (0/11) and the Brugada syndrome penetrance around 7% (0/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-3.9 0.645 -4.11 0.946 1 9
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
27287068 2016 1 0 0 1
LITERATURE, COHORT, AND GNOMAD: - 1 1 0 0 -
VARIANT FEATURES ALONE: - 15 15 0 0 - -
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.

Functional Data

Peak and late/persistent current are relative to wildtype (100% being no different from wildtype). V0.5 act/inact are the voltages at which half of the maximal current is reached during an activation and inactivation protocol, each is in units of mV and relative to wildtype.
PubMed ID Year Cell Type Peak Current (%WT) V1/2 Act. (mV) V1/2 Inact. (mV) Late/Persistent Current (%WT)
27287068 2016 Oocytes 105

S262G has 62 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
364 12
271 14 L271V,
266 6 L266H,
363 12
404 13 L404Q, L404V,
1544 13 T1544P,
270 12 Q270K,
360 14
1627 10
396 12 V396L, V396A,
1624 14 V1624I,
355 12 F355C, F355I,
1538 13
254 13
401 15 S401P,
1634 14 L1634P,
1543 10 V1543L, V1543A,
1542 7
361 9
260 6
366 11
365 9
258 6 V258A,
1546 7 M1546T,
369 12 M369K,
1545 11
1630 9 I1630R, I1630V,
1626 14 R1626P, R1626L, R1626C, R1626H,
267 9
262 0 S262G,
357 13
256 10
399 14
272 15
362 7
261 5
1628 12
1632 15 R1632C, R1632H, R1632L,
1539 11 C1539Y, C1539F,
392 13
255 11
269 10
395 13
264 7
259 5
1633 12
1548 14 G1548K, E1548K,
265 5 A265V,
253 14
358 7
263 4 V263I,
359 11 A359T, p.A359PfsX12,
1629 15 R1629G, R1629X, R1629Q,
1547 13 V1547L,
1541 12
1540 13
1631 12 G1631D,
368 13
268 10 G268S,
257 9
400 13 G400A, G400R, G400E,
1623 15 R1623Q, c.4867delC, R1623L, R1623X,