SCN5A Variant T631A Detail

We estimate the penetrance of LQTS for SCN5A T631A around 20% and the Brugada syndrome penetrance around 35%. SCN5A T631A was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. T631A is not present in gnomAD. T631A has been functionally characterized in 0 papers. This residue is located in a 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 (3 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 T631A around 20% (1/10) and the Brugada syndrome penetrance around 35% (3/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.526 52 25
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 11 1 3 - -
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.

T631A 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
616 15 S616N,
617 14
618 14 L618F,
619 13 L619F,
620 13 R620H, R620C,
621 12
622 11
623 11 M623T,
624 10 L624Q,
625 9 E625Q, E625D, c.1872dupA,
626 8
627 8 P627L,
628 7 P628R,
629 5 D629Y,
630 4 T630M,
631 0 c.1890G>A, c.1890+5G>A, p.T631VfsX101,
632 4 T632M,
633 5
634 7 S634W, S634L,
635 8
636 8 E636K,
637 9 P637L,
638 10 G638D,
639 11 G639R, G639A,
640 11 P640S, P640A, P640L,
641 12
642 13
643 13
644 14
645 14
646 15 p.Q646RfsX5, c.1936delC,