SCN5A Variant S634L Detail

We estimate the penetrance of LQTS for SCN5A S634L around 4% and the Brugada syndrome penetrance around 6%. SCN5A S634L was found in a total of 8 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. S634L is present in 8 alleles in gnomAD. S634L has been functionally characterized in 0 papers. This residue is located in a Mild_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 (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 S634L around 4% (0/18) and the Brugada syndrome penetrance around 6% (1/18).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-1.53 0.704 -0.49 0.499 8 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
LITERATURE, COHORT, AND GNOMAD: - 8 8 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.

S634L 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
619 15 L619F,
620 14 R620C, R620H,
621 14
622 13
623 13 M623T,
624 12 L624Q,
625 11 c.1872dupA, E625Q, E625D,
626 11
627 10 P627L,
628 9 P628R,
629 8 D629Y,
630 8 T630M,
631 7 c.1890G>A, c.1890+5G>A, p.T631VfsX101,
632 5 T632M,
633 4
634 0 S634L, S634W,
635 4
636 5 E636K,
637 7 P637L,
638 8 G638D,
639 8 G639R, G639A,
640 9 P640A, P640S, P640L,
641 10
642 11
643 11
644 12
645 13
646 13 p.Q646RfsX5, c.1936delC,
647 14 A647D, A647V, A647S,
648 14 P648L,
649 15 C649Y, C649R,