SCN5A Variant c.3480delT Detail

We estimate the penetrance of LQTS for SCN5A c.3480delT around 7% and the Brugada syndrome penetrance around 41%. SCN5A c.3480delT was found in a total of 3 carriers in 1 papers and/or in gnomAD: 2 had Brugada syndrome, 0 had LQTS. c.3480delT is not present in gnomAD. c.3480delT has been functionally characterized in 1 papers. This residue is located in a Mild_Hotspot region for Brugada syndrome and a Mild_Hotspot region for LQTS. In silico predictions, functional data (if available), and location in structure are equivalent to phenotyping 10 individuals for Brugada syndrome (3 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.3480delT around 7% (0/13) and the Brugada syndrome penetrance around 41% (5/13).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA None 37 11
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
19279983 2009 3 0 2 0
LITERATURE, COHORT, AND GNOMAD: - 3 1 0 2 -
VARIANT FEATURES ALONE: - 15 12 0 3 - -
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)
19279983 2009 HEK 0

c.3480delT has 31 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
1146 15
1147 14 T1147I, T1147N, T1147S,
1148 14 A1148S, A1148T,
1149 13
1150 13
1151 12
1152 11 E1152X,
1153 11 Q1153H,
1154 10 I1154N,
1155 9 P1155S,
1156 8 D1156G,
1157 8
1158 7 G1158S,
1159 5
1160 4
1161 0 c.3480delT,
1162 4
1163 5 D1163G, D1163E, D1163Y,
1164 7 P1164T,
1165 8 E1165Q, E1165D, p.E1165RfsX6,
1166 8 D1166N,
1167 9 C1167Y,
1168 10 F1168L,
1169 11 T1169I,
1170 11
1171 12 c.3511+10C>T,
1172 13
1173 13 V1173D,
1174 14 R1174W, R1174G,
1175 14 R1175H,
1176 15