SCN5A Variant I1770S Detail

We estimate the penetrance of LQTS for SCN5A I1770S around 22% and the Brugada syndrome penetrance around 12%. SCN5A I1770S was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I1770S is not present in gnomAD. I1770S has been functionally characterized in 0 papers. This residue is located in a Non_Hotspot region for Brugada syndrome and a Mild_Hotspot region for LQTS. In silico predictions, functional data (if available), and location in structure are equivalent to phenotyping 10 individuals for Brugada syndrome (1 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 I1770S around 22% (1/10) and the Brugada syndrome penetrance around 12% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.986 6 26
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 1 1 - -
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.

I1770S has 76 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
403 10
939 15 L939F,
1659 10
404 14 L404V, L404Q,
1778 13
1480 13 c.4437+5G>A, c.4438-1C>T,
1773 6
1765 10
1653 6
1472 12 p.N1472del, N1472S,
1771 5 I1771T,
401 14 S401P,
1652 9 M1652T, M1652R,
1777 11 V1777L, V1777M,
1320 12 M1320I,
1764 11 c.5290delG, V1764F,
409 12 L409P, L409V,
1650 10 L1650F,
1656 6
1477 8 K1477N,
1471 12
1779 15 T1779M,
1762 13 I1762M, p.I1762del,
1470 9
1466 11 c.4396_4397insG,
1478 14 K1478E,
1776 11
1767 6 Y1767C,
1660 8 I1660V, I1660S,
1654 10
1648 13
1769 4
402 11 F402L,
1766 7 M1766T, M1766L, M1766V,
1319 11 G1319V,
1649 10 A1649V,
1768 7 I1768V,
1774 6 N1774D, c.5321_5324dupACTT,
1473 6 F1473S, F1473C,
1468 14 V1468A, V1468F,
1663 13
399 14
405 13
1657 6
1474 10
1662 14
1324 13
1327 13
1318 14
1330 15 A1330P, A1330D, A1330T,
1772 7 L1772V,
1323 9 V1323G,
410 11 A410V,
1770 0 I1770V,
1651 13
413 15 A413T, A413E,
408 15
1322 9 c.3963+4A>G, c.3963+2T>C,
407 12
1326 11 A1326S,
1763 11 V1763L, V1763M,
1467 13
1476 11 Q1476X, Q1476R,
1775 11 p.F1775LfsX15, F1775V,
1661 12 G1661R, G1661E,
1655 9
1475 14 p.Q1475NfsX6, Q1475L,
1469 10 I1469V,
406 9 N406S, N406K,
1325 14 N1325S,
398 12
1647 15
400 14 G400E, G400R, G400A,
1646 14
1664 13
1658 11