SCN5A Variant p.L1339del Detail

We estimate the penetrance of LQTS for SCN5A p.L1339del around 29% and the Brugada syndrome penetrance around 9%. SCN5A p.L1339del was found in a total of 2 carriers in 1 papers and/or in gnomAD: 0 had Brugada syndrome, 1 had LQTS. p.L1339del is present in 1 alleles in gnomAD. p.L1339del has been functionally characterized in 1 papers. This residue is located in a Non_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 (1 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A p.L1339del around 29% (2/12) and the Brugada syndrome penetrance around 9% (1/12).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA None 6 25
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: - 2 1 1 0 -
VARIANT FEATURES ALONE: - 15 13 1 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

p.L1339del has 44 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
821 12
1340 5 V1340I,
1457 14
1757 14
1339 0 p.L1339del, L1339F,
1461 11 T1461S,
1333 11
1344 9 F1344S, F1344L,
731 14 T731I,
819 11
826 12 N826D,
818 11
825 8
1348 15 F1348L,
1464 12 L1464P, c.4389_4396delCCTCTTTA,
822 7 W822X, W822C,
1346 10 L1346I, L1346P,
1341 7
1334 10 I1334V,
1468 14 V1468A, V1468F,
1462 14
728 14 V728I,
823 11 P823T,
1330 15 A1330D, A1330T, A1330P,
827 12
1460 14 F1460L,
816 13 F816Y, F816L,
1338 6 L1338V,
1409 13 Y1409X, Y1409C,
815 13
1343 6
1345 10 W1345C,
1337 7
1342 6
1332 12 P1332L, P1332Q,
1465 12 p.F1465_L1480dup,
1331 13 I1331V,
1761 15 L1761H, c.5280delG, L1761F,
1347 12
1336 6
824 7
829 13
1335 8 M1335R,
828 10 L828V,