SCN5A Variant A1330T Detail

We estimate the penetrance of LQTS for SCN5A A1330T around 66% and the Brugada syndrome penetrance around 4%. SCN5A A1330T was found in a total of 7 carriers in 6 papers and/or in gnomAD: 0 had Brugada syndrome, 5 had LQTS. A1330T is not present in gnomAD. A1330T has been functionally characterized in 7 papers. This residue is located in a Non_Hotspot region for Brugada syndrome and a Hotspot region for LQTS. In silico predictions, functional data (if available), and location in structure are equivalent to phenotyping 10 individuals for Brugada syndrome (0 diagnosed with Brugada syndrome) and 5 individuals for LQTS (2 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A A1330T around 66% (7/17) and the Brugada syndrome penetrance around 4% (0/17).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-3.9 1 0.94 0.956 5 77
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
16039271 2005 5 1 0 0
12566525 2003 1 1 0 0
26669661 2016 7 5 0 0
25904541 2015 1 1 0 0
27566755 2016 5 5 0 0
30059973 2018 1 1 0 0
LITERATURE, COHORT, AND GNOMAD: - 7 2 5 0 -
VARIANT FEATURES ALONE: - 15 13 2 0 - -
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)
30059973 2018
12566525 2003
26669661 2016
29017927 2017
25904541 2015
27566755 2016
16039271 2005 HEK 129 2.4 6.9

A1330T has 49 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
1328 6 V1328M,
1765 12
1757 11
1472 6 N1472S, p.N1472del,
1339 15 p.L1339del, L1339F,
1320 15 M1320I,
1764 14 c.5290delG, V1764F,
1333 5
1477 15 K1477N,
1471 10
1762 8 p.I1762del, I1762M,
1470 11
1464 13 L1464P, c.4389_4396delCCTCTTTA,
1466 11 c.4396_4397insG,
944 13
1660 15 I1660V, I1660S,
1329 3 G1329S,
1769 13
1766 9 M1766T, M1766L, M1766V,
1768 15 I1768V,
1479 13
1473 9 F1473C, F1473S,
1334 5 I1334V,
1468 7 V1468F, V1468A,
1663 14
1474 13
1759 14 S1759C,
1324 10
1327 6
1758 11 p.I1758del, I1758V,
1330 0 A1330T, A1330D, A1330P,
1323 11 V1323G,
1338 11 L1338V,
1770 15 I1770V,
1322 12 c.3963+2T>C, c.3963+4A>G,
1337 10
1326 6 A1326S,
1763 11 V1763L, V1763M,
1332 5 P1332Q, P1332L,
1465 10 p.F1465_L1480dup,
1467 11
1476 11 Q1476R, Q1476X,
1331 4 I1331V,
1761 12 c.5280delG, L1761F, L1761H,
1475 12 Q1475L, p.Q1475NfsX6,
1469 7 I1469V,
1336 10
1325 9 N1325S,
1335 8 M1335R,