SCN5A Variant L736P Detail

We estimate the penetrance of LQTS for SCN5A L736P around 43% and the Brugada syndrome penetrance around 30%. SCN5A L736P was found in a total of 1 carriers in 1 papers and/or in gnomAD: 0 had Brugada syndrome, 1 had LQTS. L736P is not present in gnomAD. L736P has been functionally characterized in 1 papers. This residue is located in a 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 (3 diagnosed with Brugada syndrome) and 5 individuals for LQTS (1 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A L736P around 43% (2/11) and the Brugada syndrome penetrance around 30% (3/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-4.65 0.924 -4.04 0.94 42 45
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 1 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)
30059973 2018

L736P has 49 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
1403 11
1357 11 A1357V,
742 10 T742A,
811 13 R811H, R811G, c.2435_2436+3delTGGTAinsCGCCT,
733 7 F733L,
741 8 p.M741_T742delinsI ,
808 13 R808P, R808C, R808H,
745 7
1352 12
1406 11 G1406R, G1406E,
746 10 E746K,
1351 14 M1351R, M1351V,
739 11
812 14 L812Q,
1350 9 I1350T, I1350L,
731 10 T731I,
1353 9 V1353M,
1407 12
737 5
1358 14 G1358W, G1358R,
1404 8
750 13 Q750R,
1349 11
749 7
743 13
1346 12 L1346I, L1346P,
728 14 V728I,
747 13 E747A,
1408 13 G1408R,
735 4 A735V, A735T, A735E,
732 8
734 8 c.2201dupT, M734V,
756 15
1401 15
1354 11
744 12
738 6
752 12 G752R,
1405 8 V1405M, V1405L,
740 10 p.N740del,
1409 15 Y1409C, Y1409X,
751 14 V751I, V751F,
736 0 L736P,
730 11 N730K,
753 12
1347 15
729 12 p.L729del,
748 9 M748I,
1402 13