SCN5A Variant P1655T Detail

We estimate the penetrance of LQTS for SCN5A P1655T around 43% and the Brugada syndrome penetrance around 22%. SCN5A P1655T was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. P1655T is not present in gnomAD. P1655T has been functionally characterized in 0 papers. This residue is located in a Mild_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 (2 diagnosed with Brugada syndrome) and 5 individuals for LQTS (2 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A P1655T around 43% (2/10) and the Brugada syndrome penetrance around 22% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.934 25 57
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 2 2 - -
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.

P1655T has 43 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 11
1659 6
1480 14 c.4438-1C>T, c.4437+5G>A,
1773 14
1653 6
1315 15
1771 11 I1771T,
1652 8 M1652R, M1652T,
1314 13 c.3940_3941delCT,
1320 10 M1320I,
1650 10 L1650F,
1656 4
1477 13 K1477N,
1767 10 Y1767C,
1660 9 I1660V, I1660S,
1654 4
1648 12
1769 13
402 14 F402L,
1766 14 M1766V, M1766L, M1766T,
1319 8 G1319V,
1649 11 A1649V,
1768 15 I1768V,
1774 11 c.5321_5324dupACTT, N1774D,
1473 14 F1473C, F1473S,
1663 13
399 12
1657 6
1662 10
1324 15
1317 10 F1317C,
1318 9
1321 13 R1321K,
1323 11 V1323G,
1770 9 I1770V,
1651 9
1322 11 c.3963+4A>G, c.3963+2T>C,
1661 10 G1661R, G1661E,
1655 0
398 12
1647 14
1664 14
1658 5