SCN5A Variant L844P Detail

We estimate the penetrance of LQTS for SCN5A L844P around 17% and the Brugada syndrome penetrance around 49%. SCN5A L844P was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L844P is not present in gnomAD. L844P has been functionally characterized in 0 papers. This residue is located in a 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 (4 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 L844P around 17% (0/10) and the Brugada syndrome penetrance around 49% (4/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.983 73 19
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 11 0 4 - -
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.

L844P has 54 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
888 14
848 6 I848F,
937 14
895 15 L895F,
839 9 L839P,
842 7
240 12 V240M,
231 11 c.692_693delCA,
1455 12
1452 14
926 14
237 14
228 14 K228R,
138 14 M138I,
227 12 L227P,
836 11 V836M,
234 9 P234S,
1451 14 V1451L, V1451D,
142 12
934 12
933 13
229 9
851 11 p.F851CfsX19, c.2550_2551dupGT, c.2552_2553dupGT, F851L,
852 13
845 5 c.2533delG,
232 9 V232F, V232I,
892 15 F892I,
849 10
226 12 A226G, A226V,
235 11 G235R, c.704-1G>C, c.703+1G>A,
840 5
843 5 T843A,
1456 14
930 12 c.2788-6C>T, c.2787+17_2787+18insACACACACACACACACACACACA,
1459 14 c.4376_4379delTCTT,
837 9
239 10 I239V, I239V ,
230 8 I230M, I230V, I230T,
242 15 A242D,
841 6 N841K, p.N841TfsX2,
236 10
847 6
846 7 L846R,
238 13
233 6
838 10
141 15 I141V, I141N,
853 15
844 0 L844RfsX3,
850 11 V850M, c.2549_2550insTG,
243 13
835 13 S835A, S835L,
145 13
931 14