SCN5A Variant M1651I Detail

We estimate the penetrance of LQTS for SCN5A M1651I around 58% and the Brugada syndrome penetrance around 17%. SCN5A M1651I was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. M1651I is not present in gnomAD. M1651I 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 (1 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 M1651I around 58% (2/10) and the Brugada syndrome penetrance around 17% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.904 16 79
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 12 2 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.

M1651I has 51 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 15
1643 12 I1643L,
404 14 L404V, L404Q,
1778 12
1653 7
1635 12
1771 11 I1771T,
1652 6 M1652T, M1652R,
1634 9 L1634P,
1777 13 V1777L, V1777M,
1650 6 L1650F,
260 15
1656 11
1641 14
1779 15 T1779M,
1776 15
1787 13 S1787N,
1767 14 Y1767C,
1654 6
1648 5
1649 6 A1649V,
1774 10 N1774D, c.5321_5324dupACTT,
1644 9 R1644L, R1644H, R1644C,
256 13
399 12
1657 11
1781 15 E1781G, E1781D,
1789 12
1645 10 T1645M,
1788 10 c.5361_5364delTGAG,
1770 13 I1770V,
1638 14 R1638X, R1638Q,
1651 0
1500 15 p.K1500del,
1633 14
1591 13 W1591X,
1637 12
1792 12 D1792V, D1792Y, D1792N,
1636 15
407 13
1775 12 p.F1775LfsX15, F1775V,
1642 13 G1642E,
1655 9
1631 12 G1631D,
1590 14
398 15
1647 6
400 14 G400E, G400R, G400A,
1646 9
1658 11