SCN5A Variant H557L Detail

We estimate the penetrance of LQTS for SCN5A H557L around 3% and the Brugada syndrome penetrance around 10%. SCN5A H557L was found in a total of 1 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. H557L is present in 1 alleles in gnomAD. H557L has been functionally characterized in 0 papers. This residue is located in a Non_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 H557L around 3% (0/11) and the Brugada syndrome penetrance around 10% (1/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-4.55 0.276 -1.13 0.665 1 0
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: - 1 1 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.

H557L 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
542 15
543 14 F543L,
544 14
545 13
546 13
547 12
548 11
549 11
550 10
551 9 A551T, A551V,
552 8 G552R, G552W,
553 8 E553K, E553X,
554 7 S554I, S554N,
555 5 E555K,
556 4
557 0 H557Y, H557L, H557Q,
558 4 H558R,
559 5 T559R, T559I,
560 7
561 8
562 8
563 9 V563G,
564 10
565 11
566 11
567 12 L567Q,
568 13 R568C, R568H,
569 13 R569W, R569Q, c.1705dupC,
570 14 T570N,
571 14 S571I,
572 15 A572F, A572D, A572S, A572V,