SCN5A Variant c.4066_4068delTT Detail

We estimate the penetrance of LQTS for SCN5A c.4066_4068delTT around 2% and the Brugada syndrome penetrance around 59%. SCN5A c.4066_4068delTT was found in a total of 3 carriers in 1 papers and/or in gnomAD: 3 had Brugada syndrome, 0 had LQTS. c.4066_4068delTT is not present in gnomAD. c.4066_4068delTT has been functionally characterized in 1 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 c.4066_4068delTT around 2% (0/13) and the Brugada syndrome penetrance around 59% (7/13).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA None 68 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
21397042 2011 3 0 3 0
LITERATURE, COHORT, AND GNOMAD: - 3 0 0 3 -
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.

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)
21397042 2011

c.4066_4068delTT has 73 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 4
1403 9
1357 6 A1357V,
1430 10 D1430N,
808 13 R808C, R808P, R808H,
1352 5
1426 13
1406 13 G1406R, G1406E,
1445 12 Y1445H,
1453 12
1361 11
1447 13
1444 13 L1444I,
1351 9 M1351V, M1351R,
739 11
1397 13 c.4190delA, c.4189delT,
1449 8 Y1449C, Y1449S,
1452 14
812 15 L812Q,
1350 11 I1350T, I1350L,
1429 9
1442 15 Y1442N, Y1442C,
806 14 V806M,
1450 9
1398 11 V1398M,
1411 10
1451 14 V1451D, V1451L,
1353 7 V1353M,
1407 11
737 12
1410 14
1358 8 G1358W, G1358R,
1362 13 R1362S, c.4083delG,
1433 9 G1433W, G1433R, G1433V,
1438 12 P1438L,
1348 11 F1348L,
1404 11
1423 14 D1423H,
1437 15
1349 10
1431 7 S1431C,
1422 15 M1422R,
1346 15 L1346P, L1346I,
805 13 S805L,
1359 5 K1359M, K1359N,
1356 0 c.4066_4068delTT,
1434 8 c.4299G>A, c.4299+28C>T, c.4299+1G>T, c.4299delG, c.4300-1G>A, c.4300-2A>T, c.4299_4300insG, c.4299+1delG, c.4299+2T>A, Y1434X,
1412 10 L1412F,
1408 9 G1408R,
1435 14
1360 7 F1360C,
1401 9
1425 10
1354 8
1427 8 A1427E, A1427S,
1446 8
1424 9 I1424V,
738 13
1432 12 R1432S, R1432G,
1448 13 I1448T, I1448L,
1439 15 Q1439H, Q1439R,
1405 12 V1405M, V1405L,
809 13
1409 14 Y1409X, Y1409C,
1400 11 V1400I,
1421 15
1443 11 N1443S,
1347 14
1415 13
1428 6 A1428V, A1428S,
1436 14
1414 15 Q1414H,
1402 5