SCN5A Variant K1399T Detail

We estimate the penetrance of LQTS for SCN5A K1399T around 4% and the Brugada syndrome penetrance around 23%. SCN5A K1399T was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. K1399T is not present in gnomAD. K1399T 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 (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 K1399T around 4% (0/10) and the Brugada syndrome penetrance around 23% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.884 27 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: - 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.

K1399T has 58 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
1403 12
1746 15 A1746V, A1746T,
1724 10
1426 15
1406 13 G1406E, G1406R,
1715 10
1361 12
1687 14
1726 13
739 15
1395 15
1745 12
1397 7 c.4189delT, c.4190delA,
1743 13 G1743R, G1743E,
1723 6 T1723N,
1725 11 P1725L,
1398 5 V1398M,
1411 11
1407 10
1410 11
1716 13 p.L1716SfsX71,
1714 9 D1714G,
1688 15
1358 15 G1358W, G1358R,
1396 10
1404 13
1423 11 D1423H,
1744 13 S1744I,
1362 12 c.4083delG, R1362S,
1378 13 V1378M,
1721 8
1712 14 G1712C, G1712S,
1727 14
1719 9
1366 14 Q1366R, Q1366H,
1408 12 G1408R,
1420 12 G1420R, G1420V, G1420D, G1420P,
1728 15 C1728W, C1728R, C1728Y,
1360 10 F1360C,
1401 8
1399 0
1427 12 A1427E, A1427S,
1424 11 I1424V,
1748 14 G1748D, p.G1748del,
1683 14
1364 13 I1364V,
1400 6 V1400I,
1718 6 S1718R,
1717 9 L1717P,
1722 9 N1722D,
1686 10
1749 13 I1749N,
1720 11 c.5157delC,
1428 15 A1428V, A1428S,
1685 10
1414 12 Q1414H,
1402 12
1413 15