SCN5A Variant K590Q Detail

We estimate the penetrance of LQTS for SCN5A K590Q around 3% and the Brugada syndrome penetrance around 10%. SCN5A K590Q was found in a total of 1 carriers in 1 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. K590Q is present in 1 alleles in gnomAD. K590Q has been functionally characterized in 1 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 K590Q 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 (%)
-2.68 0.997 1.07 0.783 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
28878402 2017 1 0 0 1 AF, AVB
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.

Functional Data

Peak and late/persistent current are relative to wildtype (100% being no different from wildtype). V0.5 act/inact are the voltages at which half of the maximal current is reached during an activation and inactivation protocol, each is in units of mV and relative to wildtype.
PubMed ID Year Cell Type Peak Current (%WT) V1/2 Act. (mV) V1/2 Inact. (mV) Late/Persistent Current (%WT)
28878402 2017

K590Q 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
575 15
576 14
577 14 S577N,
578 13 P578R, P578T,
579 13 G579R,
580 12
581 11 S581L,
582 11
583 10 P583L,
584 9 G584R,
585 8
586 8 p.586_587delAL, A586T, A586G,
587 7
588 5 H588R, H588N,
589 4
590 0 K590Q,
591 4
592 5 N592K, N592S,
593 7
594 8
595 8
596 9 D596G,
597 10 C597G, C597Y,
598 11
599 11 G599R,
600 12
601 13 V601A,
602 13
603 14
604 14 L604V,
605 15 G605E,