SCN5A Variant I966T Detail

We estimate the penetrance of LQTS for SCN5A I966T around 18% and the Brugada syndrome penetrance around 17%. SCN5A I966T was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I966T is not present in gnomAD. I966T has been functionally characterized in 0 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 (1 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 I966T around 18% (0/10) and the Brugada syndrome penetrance around 17% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.939 16 20
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
LITERATURE, COHORT, AND GNOMAD: - 0 0 0 0 -
VARIANT FEATURES ALONE: - 15 14 0 1 - -
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.

I966T 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
951 15 c.2850delT, D951X,
952 14 E952K,
953 14 D953Y, D953E,
954 13 R954G,
955 13 p.E955DfsX74,
956 12 M956T, M956I,
957 11
958 11
959 10 L959P,
960 9 Q960K,
961 8
962 8
963 7
964 5 A964G,
965 4 R965H, R965L, R965C,
966 0
967 4 Q967R,
968 5
969 7 G969C, G969S,
970 8
971 8 R971C, R971H,
972 9 c.2914_2923delTTTGTCAAGC,
973 10
974 11 K974D,
975 11 R975W, R975Q,
976 12
977 13
978 13
979 14 D979H,
980 14
981 15 C981F,