SCN5A Variant I1576T Detail

We estimate the penetrance of LQTS for SCN5A I1576T around 3% and the Brugada syndrome penetrance around 41%. SCN5A I1576T was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I1576T is not present in gnomAD. I1576T has been functionally characterized in 0 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 (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 I1576T around 3% (0/10) and the Brugada syndrome penetrance around 41% (4/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.752 60 0
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 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.

I1576T 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
1569 10 A1569P,
1525 10 V1525A, V1525M,
1524 10 I1524T,
1586 10
1518 11
1531 14
1568 12
1587 13 F1587V,
1602 14
1534 13
1522 13
1575 5 C1575S,
1600 12
1571 10 F1571C,
1523 14 D1523N,
1521 8 I1521K, I1521T,
1527 15 K1527R,
1572 6
1570 10 p.1570_F1571insI, p.I1570dup, I1570V,
1599 10
1526 14 T1526P,
1583 12 R1583H, R1583C,
1580 7
1603 13 I1603F,
1576 0
1517 13
1519 13
1596 11 F1596C, F1596I,
1584 15
1597 14 V1597M,
1530 11
1573 4
1581 9 A1581S,
1513 14
1520 14
1593 15 I1593M,
1595 12
1574 7 E1574K, c.4719C>T,
1592 12
1578 7 c.4732_4733dupAA,
1582 11 L1582P,
1579 6 L1579fsX53,
1598 14 V1598A,
1577 5