SCN5A Variant R1632L Detail

We estimate the penetrance of LQTS for SCN5A R1632L around 11% and the Brugada syndrome penetrance around 49%. SCN5A R1632L was found in a total of 1 carriers in 2 papers and/or in gnomAD: 1 had Brugada syndrome, 0 had LQTS. R1632L is not present in gnomAD. R1632L has been functionally characterized in 2 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 R1632L around 11% (0/11) and the Brugada syndrome penetrance around 49% (5/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-6.48 1 -4.07 0.972 62 15
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
21656940 2011 1 0 1 0
30059973 2018 1 1 0 0
LITERATURE, COHORT, AND GNOMAD: - 1 0 0 1 -
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.

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)
21656940 2011
30059973 2018

R1632L has 59 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
1525 13 V1525A, V1525M,
1627 11
1586 12
1567 14 F1567L,
1624 14 V1624I,
1536 12
1538 7
1531 9
1635 6
1587 15 F1587V,
1634 8 L1634P,
1534 8
1542 11
1575 12 C1575S,
260 15
1571 11 F1571C,
1570 14 p.1570_F1571insI, I1570V, p.I1570dup,
1529 14
1599 14
1630 6 I1630V, I1630R,
1532 11 V1532I, V1532F,
1626 12 R1626L, R1626P, R1626H, R1626C,
1644 15 R1644L, R1644C, R1644H,
1625 12
262 15 S262G,
1596 13 F1596C, F1596I,
1628 8
1589 9
1632 0 R1632L, R1632C, R1632H,
1597 13 V1597M,
1530 12
1539 9 C1539F, C1539Y,
1573 15
1535 5
1537 11
1594 9 F1594S,
1638 14 R1638Q, R1638X,
259 12
1588 14 T1588I,
1633 6
1591 5 W1591X,
1593 11 I1593M,
1595 7
1637 12
1636 8
263 13 V263I,
1629 5 R1629X, R1629Q, R1629G,
1574 10 c.4719C>T, E1574K,
1533 12 T1533I,
1541 12
1592 8
1578 11 c.4732_4733dupAA,
1540 13
1528 15
1631 5 G1631D,
1590 9
1647 15
1598 12 V1598A,
1577 15