SCN5A Variant L1634P Detail

We estimate the penetrance of LQTS for SCN5A L1634P around 54% and the Brugada syndrome penetrance around 20%. SCN5A L1634P was found in a total of 1 carriers in 1 papers and/or in gnomAD: 0 had Brugada syndrome, 1 had LQTS. L1634P is not present in gnomAD. L1634P has been functionally characterized in 1 papers. This residue is located in a Mild_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 (2 diagnosed with Brugada syndrome) and 5 individuals for LQTS (2 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A L1634P around 54% (3/11) and the Brugada syndrome penetrance around 20% (2/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-6.48 0.999 -5.5 0.982 20 62
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 2 2 - -
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

L1634P has 57 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
403 14
1643 9 I1643L,
404 15 L404V, L404Q,
1627 14
1538 13
1531 14
1635 6
1652 14 M1652T, M1652R,
1634 0 L1634P,
1542 14
1650 11 L1650F,
260 10
1641 13
258 14 V258A,
1639 12 G1639A,
1654 13
1648 11
1630 8 I1630V, I1630R,
1532 14 V1532I, V1532F,
1649 12 A1649V,
1644 8 R1644H, R1644C, R1644L,
1640 11
262 14 S262G,
256 9
399 14
1628 11
1589 13
1789 13
1632 8 R1632L, R1632H, R1632C,
255 12
1539 13 C1539F, C1539Y,
1645 12 T1645M,
1535 11
1788 15 c.5361_5364delTGAG,
1594 14 F1594S,
264 15
1638 10 R1638Q, R1638X,
1651 9
259 9
1633 5
1591 9 W1591X,
1595 15
1637 6
253 14
1792 15 D1792N, D1792Y, D1792V,
1636 7
263 12 V263I,
1629 13 R1629X, R1629Q, R1629G,
1642 12 G1642E,
1592 14
1631 5 G1631D,
1590 12
252 14
1647 7
257 13
400 15 G400A, G400R, G400E,
1646 11