SCN5A Variant T632A Detail

We estimate the penetrance of LQTS for SCN5A T632A around 17% and the Brugada syndrome penetrance around 28%. SCN5A T632A was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. T632A is not present in gnomAD. T632A 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 (2 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 T632A around 17% (0/10) and the Brugada syndrome penetrance around 28% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.655 37 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 13 0 2 - -
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.

T632A 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
617 15
618 14 L618F,
619 14 L619F,
620 13 R620C, R620H,
621 13
622 12
623 11 M623T,
624 11 L624Q,
625 10 c.1872dupA, E625Q, E625D,
626 9
627 8 P627L,
628 8 P628R,
629 7 D629Y,
630 5 T630M,
631 4 p.T631VfsX101, c.1890+5G>A, c.1890G>A,
632 0 T632M,
633 4
634 5 S634W, S634L,
635 7
636 8 E636K,
637 8 P637L,
638 9 G638D,
639 10 G639A, G639R,
640 11 P640A, P640L, P640S,
641 11
642 12
643 13
644 13
645 14
646 14 c.1936delC, p.Q646RfsX5,
647 15 A647D, A647V, A647S,