SCN5A Variant I1593T Detail

We estimate the penetrance of LQTS for SCN5A I1593T around 36% and the Brugada syndrome penetrance around 9%. SCN5A I1593T was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I1593T is not present in gnomAD. I1593T has been functionally characterized in 0 papers. This residue is located in a Non_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 (0 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 I1593T around 36% (1/10) and the Brugada syndrome penetrance around 9% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.964 1 47
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 14 1 0 - -
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.

I1593T has 41 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
1586 6
1624 14 V1624I,
1635 14
1587 6 F1587V,
1602 15
1601 13 L1601H,
1575 10 C1575S,
1600 11
1571 14 F1571C,
1572 15
1599 11
1583 14 R1583C, R1583H,
1580 15
1630 15 I1630R, I1630V,
1626 15 R1626P, R1626C, R1626L, R1626H,
1625 11
1585 13 Y1585C,
1576 15
1596 6 F1596C, F1596I,
1628 11
1589 6
1584 12
1632 11 R1632L, R1632C, R1632H,
1597 7 V1597M,
1594 5 F1594S,
1588 8 T1588I,
1581 15 A1581S,
1591 8 W1591X,
1593 0 I1593M,
1595 7
1629 10 R1629Q, R1629X, R1629G,
1574 12 c.4719C>T, E1574K,
1592 5
1578 11 c.4732_4733dupAA,
1631 13 G1631D,
1590 5
1622 15
1582 12 L1582P,
1579 11 L1579fsX53,
1598 10 V1598A,
1577 15