SCN5A Variant A447T Detail

We estimate the penetrance of LQTS for SCN5A A447T around 16% and the Brugada syndrome penetrance around 20%. SCN5A A447T was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. A447T is not present in gnomAD. A447T has been functionally characterized in 0 papers. This residue is located in a Mild_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 (1 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 A447T around 16% (0/10) and the Brugada syndrome penetrance around 20% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.529 24 20
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 0 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.

A447T has 31 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
432 15
433 14 R433H, R433S, R433C,
434 14
435 13
436 13
437 12 A437V,
438 11 M438L, M438T,
439 11 E439K, E439V,
440 10
441 9 L441F,
442 8
443 8
444 7 E444fsX14,
445 5 H445Y, H445D, H445Q,
446 4 E446K,
447 0 c.1339-24G>A, A447S, c.1338+2T>A, A447G,
448 4
449 5 T449A, Y449C,
450 7
451 8
452 8 G452D,
453 9 V453M,
454 10
455 11
456 11 V456M,
457 12
458 13 R458H, R458C, p.R458VfsX12,
459 13 S459G,
460 14
461 14 L461V,
462 15 E462K, E462A,