SCN5A Variant M1691I Detail

We estimate the penetrance of LQTS for SCN5A M1691I around 3% and the Brugada syndrome penetrance around 43%. SCN5A M1691I was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. M1691I is not present in gnomAD. M1691I has been functionally characterized in 0 papers. This residue is located in a 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 (4 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 M1691I around 3% (0/10) and the Brugada syndrome penetrance around 43% (4/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.82 63 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 11 0 4 - -
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.

M1691I has 64 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
328 13
333 5 c.998+5G>A, c.998+1G>A,
1702 8
326 10
387 8
385 11 A385T,
1715 14
1687 9
330 10 S330F,
388 12 I388S,
1698 9 A1698T,
334 8 c.999-424_1338+81del,
332 7 A332T,
1681 14 Y1681F, c.5040_5042delTTAinsC,
1694 11
1704 13 L1704H,
327 11
1706 12 Q1706H,
1695 10 Q1695X,
376 14 R376H, R376C,
1716 13 p.L1716SfsX71,
384 10 S384T,
1688 8
1684 10 W1684R,
329 11
1676 14 M1676T, M1676I,
1692 4
386 9 G386E, G386R,
1693 6
378 10
1699 6
331 7
1712 15 G1712C, G1712S,
379 8
1680 15 A1680T, A1680P,
1703 9
1719 15
335 12 C335S, C335R,
1701 12 M1701I,
325 11 L325R,
1228 14 Y1228H, Y1228F, Y1228C,
1690 6 c.5068_5070delGA, D1690N,
324 12
1697 12
389 13 Y389H, Y389X,
1227 14
393 15
390 12
383 6
280 15 C280Y,
382 7
1696 10
1705 13
1689 5 D1689N,
1700 10
1682 14
336 14 P336L,
381 11 c.1141-3C>A, c.1140+1G>A,
1686 13
375 13
1691 0
380 11
377 14
1685 14