SCN5A Variant A242D Detail

We estimate the penetrance of LQTS for SCN5A A242D around 67% and the Brugada syndrome penetrance around 11%. SCN5A A242D was found in a total of 1 carriers in 1 papers and/or in gnomAD: 0 had Brugada syndrome, 1 had LQTS. A242D is not present in gnomAD. A242D has been functionally characterized in 1 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 (1 diagnosed with Brugada syndrome) and 5 individuals for LQTS (3 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A A242D around 67% (4/11) and the Brugada syndrome penetrance around 11% (1/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-5.86 1 -4.24 0.975 4 84
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
30059973 2018 1 1 0 0
LITERATURE, COHORT, AND GNOMAD: - 1 0 1 0 -
VARIANT FEATURES ALONE: - 15 11 3 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.

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

A242D has 63 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
414 10 M414V,
939 15 L939F,
937 11
839 15 L839P,
842 10
249 9 K249X,
247 8 V247L,
240 6 V240M,
231 15 c.692_693delCA,
193 14 W193X, W193R,
418 9 E418K,
926 13
250 12
409 13 L409V, L409P,
237 9
928 13 L928P,
925 12 I925F,
417 10
934 13
933 7
246 5
935 13 L935P,
412 8 V412D,
924 14 V924I,
927 15 N927S, N927K,
245 6 Q245K,
845 11 c.2533delG,
244 6
415 6 A415T,
940 13 S940N,
849 14
420 9
248 10
241 3
235 11 G235R, c.703+1G>A, c.704-1G>C,
840 15
843 14 T843A,
419 6 Q419X,
930 10 c.2788-6C>T, c.2787+17_2787+18insACACACACACACACACACACACA,
423 12
239 5 I239V , I239V,
230 12 I230M, I230V, I230T,
251 15
410 13 A410V,
242 0 A242D,
929 9
416 6 Y416C,
413 9 A413T, A413E,
841 12 p.N841TfsX2, N841K,
236 10
408 13
846 14 L846R,
936 10
238 7
233 14
838 12
422 11
421 13
844 15 L844RfsX3,
411 10 V411M,
243 4
932 12
931 13