SCN5A Variant I1538T Detail

We estimate the penetrance of LQTS for SCN5A I1538T around 6% and the Brugada syndrome penetrance around 10%. SCN5A I1538T was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I1538T is not present in gnomAD. I1538T has been functionally characterized in 0 papers. This residue is located in a Non_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 I1538T around 6% (0/10) and the Brugada syndrome penetrance around 10% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.979 2 3
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 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.

I1538T has 62 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
266 12 L266H,
1569 13 A1569P,
1544 10 T1544P,
270 15 Q270K,
1627 8
1567 8 F1567L,
1624 13 V1624I,
1536 8
1538 0
1531 11
1566 12
1635 12
1568 11
1634 13 L1634P,
1543 9 V1543L, V1543A,
1602 14
1534 7
1542 6
1575 13 C1575S,
1571 7 F1571C,
1572 13
1564 11
1570 10 p.1570_F1571insI, p.I1570dup, I1570V,
1529 14
1599 12
1546 12 M1546T,
1545 10
1630 6 I1630R, I1630V,
1532 11 V1532I, V1532F,
1626 8 R1626P, R1626C, R1626L, R1626H,
267 14
1625 11
1560 15 L1560F,
262 13 S262G,
1628 9
1632 7 R1632L, R1632C, R1632H,
1539 4 C1539Y, C1539F,
1597 14 V1597M,
1530 12
1573 14
1535 5
1537 5
1565 15 L1565M,
1594 13 F1594S,
259 12
1633 9
1591 12 W1591X,
1595 9
1636 12
263 12 V263I,
1629 5 R1629Q, R1629X, R1629G,
1574 10 c.4719C>T, E1574K,
1533 10 T1533I,
1563 12
1541 5
1592 13
1578 14 c.4732_4733dupAA,
1540 6
1631 9 G1631D,
1622 13
1598 11 V1598A,
1623 14 c.4867delC, R1623X, R1623Q, R1623L,