SCN5A Variant F1344L Detail

We estimate the penetrance of LQTS for SCN5A F1344L around 7% and the Brugada syndrome penetrance around 62%. SCN5A F1344L was found in a total of 1 carriers in 1 papers and/or in gnomAD: 1 had Brugada syndrome, 0 had LQTS. F1344L is not present in gnomAD. F1344L has been functionally characterized in 1 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 (5 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 F1344L around 7% (0/11) and the Brugada syndrome penetrance around 62% (6/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-5.85 0.998 2.06 0.946 92 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
LITERATURE, COHORT, AND GNOMAD: - 1 0 0 1 -
VARIANT FEATURES ALONE: - 15 10 0 5 - -
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)
20129283 2010

F1344L has 64 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
1352 15
821 14
1340 5 V1340I,
1457 8
1453 9
1455 11
1339 9 L1339F, p.L1339del,
1351 11 M1351V, M1351R,
1449 13 Y1449C, Y1449S,
1452 12
1461 7 T1461S,
812 11 L812Q,
1350 12 I1350L, I1350T,
1344 0 F1344L, F1344S,
731 13 T731I,
1450 15
819 10
826 13 N826D,
818 11
1451 15 V1451D, V1451L,
825 9
1458 12 S1458Y,
1348 7 F1348L,
1464 11 c.4389_4396delCCTCTTTA, L1464P,
1349 10
822 12 W822C, W822X,
1346 7 L1346I, L1346P,
833 15 G833R,
1341 6
831 14
1462 12
938 15
1412 12 L1412F,
823 15 P823T,
1408 14 G1408R,
942 14
1456 7
1459 13 c.4376_4379delTCTT,
734 15 M734V, c.2201dupT,
827 13
1460 9 F1460L,
816 8 F816L, F816Y,
813 13 c.2436+12G>A, c.2437-5C>A,
1454 12
1338 11 L1338V,
817 14 K817E,
1405 14 V1405L, V1405M,
1409 12 Y1409X, Y1409C,
815 9
1343 5
1345 6 W1345C,
1337 10
1342 7
1416 13 A1416G, c.4245+1G>C, c.4245+1G>A, A1416E, c.4245+2T>A,
1465 13 p.F1465_L1480dup,
1347 6
1336 13
1415 15
824 12
829 10
832 11
828 9 L828V,
1463 14 N1463Y,
1413 13