SCN5A Variant A735E Detail

We estimate the penetrance of LQTS for SCN5A A735E around 4% and the Brugada syndrome penetrance around 60%. SCN5A A735E was found in a total of 2 carriers in 2 papers and/or in gnomAD: 2 had Brugada syndrome, 0 had LQTS. A735E is not present in gnomAD. A735E has been functionally characterized in 3 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 A735E around 4% (0/12) and the Brugada syndrome penetrance around 60% (7/12).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-4.62 0.004 -2.37 0.947 72 10
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
11901046 2002 1 0 1 0
21321465 2011 1 0 1 0
LITERATURE, COHORT, AND GNOMAD: - 2 0 0 2 -
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.

Functional Data

Peak and late/persistent current are relative to wildtype (100% being no different from wildtype). V0.5 act/inact are the voltages at which half of the maximal current is reached during an activation and inactivation protocol, each is in units of mV and relative to wildtype.
PubMed ID Year Cell Type Peak Current (%WT) V1/2 Act. (mV) V1/2 Inact. (mV) Late/Persistent Current (%WT)
32533946 2020 HEK 1
11901046 2002
21321465 2011

A735E has 57 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 15
1403 12
1357 12 A1357V,
742 14 T742A,
811 12 R811G, R811H, c.2435_2436+3delTGGTAinsCGCCT,
733 7 F733L,
741 12 p.M741_T742delinsI ,
808 13 R808H, R808P, R808C,
745 11
1352 11
1406 10 G1406E, G1406R,
746 14 E746K,
1351 12 M1351R, M1351V,
739 14
812 11 L812Q,
1350 6 I1350T, I1350L,
731 6 T731I,
726 15
818 14
1353 8 V1353M,
1407 12
737 6
1410 15
1348 13 F1348L,
1404 9
750 14 Q750R,
1349 8
749 9
1346 8 L1346I, L1346P,
728 10 V728I,
1412 15 L1412F,
727 13
1408 11 G1408R,
735 0 A735E, A735T, A735V,
732 5
734 5 M734V, c.2201dupT,
756 14
814 13 R814Q,
1401 15
1354 10
738 10
752 13 G752R,
1405 6 V1405L, V1405M,
809 14
740 14 p.N740del,
1409 12 Y1409X, Y1409C,
815 11
1343 12
1345 14 W1345C,
1342 12
736 4 L736P,
730 9 N730K,
753 12
1347 11
729 10 p.L729del,
748 12 M748I,
1402 13