SCN5A Variant M741I Detail

We estimate the penetrance of LQTS for SCN5A M741I around 7% and the Brugada syndrome penetrance around 51%. SCN5A M741I was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. M741I is not present in gnomAD. M741I 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 (5 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 M741I around 7% (0/10) and the Brugada syndrome penetrance around 51% (5/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.909 78 5
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 10 0 5 - -
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.

M741I has 37 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
1355 14
1403 11
1357 10 A1357V,
742 5 T742A,
811 15 R811H, c.2435_2436+3delTGGTAinsCGCCT, R811G,
733 13 F733L,
741 0 p.M741_T742delinsI ,
808 12 R808P, R808C, R808H,
745 7
1352 14
746 5 E746K,
739 7
1350 14 I1350T, I1350L,
1353 11 V1353M,
737 7
1358 10 G1358R, G1358W,
1433 15 G1433W, G1433R, G1433V,
1404 12
750 11 Q750R,
749 8
743 7
1359 14 K1359N, K1359M,
1434 11 c.4299_4300insG, c.4300-1G>A, c.4299+1G>T, c.4299+2T>A, c.4299+1delG, c.4299+28C>T, c.4299delG, c.4300-2A>T, c.4299G>A, Y1434X,
747 11 E747A,
735 12 A735V, A735T, A735E,
1435 13
734 13 M734V, c.2201dupT,
1354 11
744 10
738 6
752 14 G752R,
1405 14 V1405M, V1405L,
740 6 p.N740del,
751 14 V751I, V751F,
736 8 L736P,
753 14
748 10 M748I,