SCN5A Variant C260G Detail

We estimate the penetrance of LQTS for SCN5A C260G around 31% and the Brugada syndrome penetrance around 9%. SCN5A C260G was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. C260G is not present in gnomAD. C260G has been functionally characterized in 0 papers. This residue is located in a Non_Hotspot region for Brugada syndrome and a Mild_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 (1 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A C260G around 31% (1/10) and the Brugada syndrome penetrance around 9% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.984 2 39
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 14 1 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.

C260G has 63 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 10
364 14
266 11 L266H,
363 15
1643 12 I1643L,
404 8 L404V, L404Q,
1627 12
396 9 V396L, V396A,
1624 15 V1624I,
254 10
401 10 S401P,
1634 10 L1634P,
250 14
1542 12
1650 12 L1650F,
361 13
260 0
366 11
365 9
258 6 V258A,
1546 13 M1546T,
369 9 M369K,
1654 15
402 14 F402L,
1630 10 I1630V, I1630R,
267 11
262 6 S262G,
256 6
399 9
397 12 I397T, I397F, I397V,
405 13
362 10
261 5
1628 12
1632 15 R1632H, R1632C, R1632L,
1539 14 C1539Y, C1539F,
392 13
255 9
395 11
251 14
264 7
1651 15
259 4
1633 11
265 9 A265V,
1637 13
408 13
253 10
1636 15
407 12
358 13
263 6 V263I,
370 14 T370M,
1631 10 G1631D,
406 14 N406K, N406S,
368 12
268 13 G268S,
252 13
398 13
1647 11
257 5
400 8 G400E, G400A, G400R,
1646 13