SCN5A Variant M1487T Detail

We estimate the penetrance of LQTS for SCN5A M1487T around 52% and the Brugada syndrome penetrance around 8%. SCN5A M1487T was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. M1487T is not present in gnomAD. M1487T has been functionally characterized in 0 papers. This residue is located in a Non_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 (0 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 M1487T around 52% (2/10) and the Brugada syndrome penetrance around 8% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.886 1 71
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 2 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.

M1487T 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
1773 14
943 12 S943N,
1486 7 p.F1486del, F1486L,
1472 15 p.N1472del, N1472S,
1777 14 V1777M, V1777L,
1485 7
1487 0 M1487L, M1487K,
1492 10
1477 13 K1477N,
1491 10 Q1491H,
1471 13
1493 12 K1493X, p.K1493del, K1493R,
1478 8 K1478E,
1776 15
944 14
1495 14 Y1495S,
1479 13
1496 14
1474 10
1481 13 G1481E, G1481V, G1481R,
1488 5 T1488R,
1780 14 E1780G,
1482 10
1476 14 Q1476X, Q1476R,
1484 6
1490 10
1475 10 p.Q1475NfsX6, Q1475L,
1483 8 Q1483H,
1489 6 E1489D,