SCN5A Variant M1335K Detail

We estimate the penetrance of LQTS for SCN5A M1335K around 21% and the Brugada syndrome penetrance around 31%. SCN5A M1335K was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. M1335K is not present in gnomAD. M1335K 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 M1335K around 21% (1/10) and the Brugada syndrome penetrance around 31% (3/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.972 40 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.

M1335K has 36 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
1328 11 V1328M,
1340 10 V1340I,
1757 10
1472 14 p.N1472del, N1472S,
1339 8 p.L1339del, L1339F,
1461 14 T1461S,
1333 6
1754 13
825 14
1762 12 p.I1762del, I1762M,
1464 13 L1464P, c.4389_4396delCCTCTTTA,
1753 14 T1753A,
822 13 W822X, W822C,
1329 10 G1329S,
1334 5 I1334V,
1341 11
1468 12 V1468F, V1468A,
823 15 P823T,
1327 12
1758 13 p.I1758del, I1758V,
1330 8 A1330T, A1330D, A1330P,
1338 6 L1338V,
1343 13
1345 15 W1345C,
1337 7
1342 11
1326 14 A1326S,
1332 5 P1332L, P1332Q,
1465 11 p.F1465_L1480dup,
1467 15
1331 6 I1331V,
1761 13 L1761F, c.5280delG, L1761H,
1469 13 I1469V,
1336 5
824 11
1335 0 M1335R,