SCN5A Variant L1702M Detail

We estimate the penetrance of LQTS for SCN5A L1702M around 3% and the Brugada syndrome penetrance around 18%. SCN5A L1702M was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L1702M is not present in gnomAD. L1702M 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 L1702M around 3% (0/10) and the Brugada syndrome penetrance around 18% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.721 20 1
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 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.

L1702M has 70 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
333 12 c.998+1G>A, c.998+5G>A,
1702 0
387 7
385 12 A385T,
1715 14
1687 12
391 11
330 13 S330F,
388 10 I388S,
1698 6 A1698T,
1673 14
1675 14
1711 12 c.5131delG,
332 11 A332T,
1707 10
1694 10
1704 7 L1704H,
1706 7 Q1706H,
1695 12 Q1695X,
376 14 R376H, R376C,
1716 12 p.L1716SfsX71,
384 14 S384T,
1688 11
1669 13
1671 15
329 14
1676 12 M1676I, M1676T,
1668 9 M1668T,
1692 6
386 9 G386E, G386R,
1672 11 S1672Y,
1693 8
378 6
1699 5
331 10
1665 12
1712 13 G1712C, G1712S,
379 9
1703 5
397 14 I397F, I397T, I397V,
1709 12 T1709M, p.T1709del, T1709R,
1701 5 M1701I,
1690 13 c.5068_5070delGA, D1690N,
1223 14 c.3667delG,
392 13
1755 14
1697 9
389 11 Y389H, Y389X,
393 10
1713 14
390 7
394 11
383 12
1708 11 T1708I,
382 7
1696 9
374 11 W374G,
1705 6
1689 11 D1689N,
1700 6
1752 15
381 11 c.1141-3C>A, c.1140+1G>A,
375 11
1691 8
1710 15 S1710L,
380 13
377 13
1679 14
1667 14 V1667I,
1664 14