SCN5A Variant c.2850delT Detail

We estimate the penetrance of LQTS for SCN5A c.2850delT around 3% and the Brugada syndrome penetrance around 45%. SCN5A c.2850delT was found in a total of 1 carriers in 2 papers and/or in gnomAD: 1 had Brugada syndrome, 0 had LQTS. c.2850delT is not present in gnomAD. c.2850delT has been functionally characterized in 2 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 (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.2850delT around 3% (0/11) and the Brugada syndrome penetrance around 45% (4/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA None 57 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
20129283 2010 1 0 1 0
29325976 2018 2 0 2 0
LITERATURE, COHORT, AND GNOMAD: - 1 0 0 1 -
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)
29325976 2018
20129283 2010

c.2850delT 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
936 15
937 14
938 14
939 13 L939F,
940 13 S940N,
941 12 S941F, S941N,
942 11
943 11 S943N,
944 10
945 9 D945G,
946 8
947 8
948 7
949 5
950 4 P950X,
951 0 c.2850delT, D951X,
952 4 E952K,
953 5 D953Y, D953E,
954 7 R954G,
955 8 p.E955DfsX74,
956 8 M956T, M956I,
957 9
958 10
959 11 L959P,
960 11 Q960K,
961 12
962 13
963 13
964 14 A964G,
965 14 R965H, R965L, R965C,
966 15