SCN5A Variant T1588I Detail

We estimate the penetrance of LQTS for SCN5A T1588I around 6% and the Brugada syndrome penetrance around 9%. SCN5A T1588I was found in a total of 1 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. T1588I is present in 1 alleles in gnomAD. T1588I 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 (0 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 T1588I around 6% (0/11) and the Brugada syndrome penetrance around 9% (0/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-4.9 0.485 -2.31 0.797 4 7
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: - 1 1 0 0 -
VARIANT FEATURES ALONE: - 15 15 0 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.

T1588I has 29 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 14 V1525M, V1525A,
1586 7
1635 13
1587 6 F1587V,
1511 13
1575 14 C1575S,
1510 10
1507 13 p.Q1507_P1509del,
1509 13 P1509T,
1583 11 R1583C, R1583H,
1580 14
1585 6 Y1585C,
1596 12 F1596I, F1596C,
1589 5
1584 9
1632 14 R1632C, R1632H, R1632L,
1597 15 V1597M,
1594 11 F1594S,
1588 0 T1588I,
1581 13 A1581S,
1591 11 W1591X,
1593 8 I1593M,
1595 12
1508 11
1592 8
1578 12 c.4732_4733dupAA,
1590 7
1582 9 L1582P,
1579 12 L1579fsX53,