SCN5A Variant M1422R Detail

We estimate the penetrance of LQTS for SCN5A M1422R around 2% and the Brugada syndrome penetrance around 26%. SCN5A M1422R was found in a total of 1 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. M1422R is present in 1 alleles in gnomAD. M1422R 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 M1422R around 2% (0/11) and the Brugada syndrome penetrance around 26% (2/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-5.42 1 -4.01 0.971 33 2
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: - 1 1 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.

M1422R 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
891 13 I891N, I891T,
880 13
888 13
890 10 I890T,
901 9 E901K, S901L,
896 10 C896S,
895 13 L895F,
1417 12
1430 13 D1430N,
1426 8
894 12 I894M,
1453 14
1715 14
1447 12
1444 13 L1444I,
372 13
1440 13 W1440X,
1449 14 Y1449C, Y1449S,
1429 11
1711 14 c.5131delG,
1450 10
887 14
1398 14 V1398M,
1411 12
1451 13 V1451L, V1451D,
886 12 H886Q, H886P,
1458 14 S1458Y,
1714 11 D1714G,
376 15 R376H, R376C,
897 11 G897R, G897E,
1423 5 D1423H,
1431 15 S1431C,
1422 0 M1422R,
1418 9
902 11
892 10 F892I,
373 12
1712 13 G1712S, G1712C,
1356 15 c.4066_4068delTT,
898 8
893 6 R893C, R893H,
1412 13 L1412F,
889 9
1420 6 G1420R, G1420D, G1420V, G1420P,
900 13
1360 14 F1360C,
1425 5
1713 15
1454 12
1427 10 A1427S, A1427E,
1446 15
1424 7 I1424V,
1448 15 I1448T, I1448L,
878 7 R878C, R878H, R878L,
1400 12 V1400I,
1421 4
885 15
1416 12 A1416G, c.4245+1G>C, A1416E, c.4245+2T>A, c.4245+1G>A,
877 12
879 6 W879R,
905 14
375 14
899 14
1710 15 S1710L,
1415 9
1428 10 A1428S, A1428V,
1419 9 K1419E,
1414 10 Q1414H,
1402 15
1413 14