SCN5A Variant L1566H Detail

We estimate the penetrance of LQTS for SCN5A L1566H around 4% and the Brugada syndrome penetrance around 21%. SCN5A L1566H was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L1566H is not present in gnomAD. L1566H has been functionally characterized in 0 papers. This residue is located in a Mild_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 (2 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 L1566H around 4% (0/10) and the Brugada syndrome penetrance around 21% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.855 24 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
LITERATURE, COHORT, AND GNOMAD: - 0 0 0 0 -
VARIANT FEATURES ALONE: - 15 13 0 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.

L1566H has 38 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
1569 6 A1569P,
1544 11 T1544P,
1567 4 F1567L,
1536 13
1538 12
1566 0
1568 7
1543 14 V1543L, V1543A,
1602 12
1558 14
1534 12
1575 15 C1575S,
1562 8
1571 9 F1571C,
1572 10
1564 7
1570 6 p.1570_F1571insI, p.I1570dup, I1570V,
1599 13
1545 14
1626 13 R1626P, R1626C, R1626L, R1626H,
1603 14 I1603F,
1606 12 T1606I,
1560 11 L1560F,
1559 11 I1559V,
1539 14 C1539Y, C1539F,
1573 11
1537 9
1565 6 L1565M,
1629 15 R1629Q, R1629X, R1629G,
1605 15 c.4813+3_4813+6dupGGGT, c.4813+2_4813+5dupTGGG, G1605D, G1605C, c.4813+5insTGGG,
1574 13 c.4719C>T, E1574K,
1533 13 T1533I,
1563 6
1541 10
1607 15
1540 10
1598 14 V1598A,
1561 9