SCN5A Variant T1488R Detail

We estimate the penetrance of LQTS for SCN5A T1488R around 68% and the Brugada syndrome penetrance around 7%. SCN5A T1488R was found in a total of 1 carriers in 1 papers and/or in gnomAD: 0 had Brugada syndrome, 1 had LQTS. T1488R is not present in gnomAD. T1488R has been functionally characterized in 1 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 (3 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A T1488R around 68% (4/11) and the Brugada syndrome penetrance around 7% (0/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-5.46 0.188 1.31 0.959 1 81
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
19716085 2009 1 1 0 0
LITERATURE, COHORT, AND GNOMAD: - 1 0 1 0 -
VARIANT FEATURES ALONE: - 15 12 3 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.

Functional Data

Peak and late/persistent current are relative to wildtype (100% being no different from wildtype). V0.5 act/inact are the voltages at which half of the maximal current is reached during an activation and inactivation protocol, each is in units of mV and relative to wildtype.
PubMed ID Year Cell Type Peak Current (%WT) V1/2 Act. (mV) V1/2 Inact. (mV) Late/Persistent Current (%WT)
19716085 2009

T1488R has 32 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
1785 14
1486 6 F1486L, p.F1486del,
1777 13 V1777M, V1777L,
1485 9
1487 5 M1487K, M1487L,
1492 8
1872 15 K1872N,
1491 6 Q1491H,
1874 14
1493 8 p.K1493del, K1493X, K1493R,
1478 11 K1478E,
1776 14
1495 12 Y1495S,
1496 13
1474 13
1481 14 G1481E, G1481R, G1481V,
1781 14 E1781D, E1781G,
1488 0 T1488R,
1784 12 E1784K, E1784X,
1780 11 E1780G,
1869 13
1482 12
1868 12
1783 14
1484 10
421 14
1497 15
1490 5
1475 14 Q1475L, p.Q1475NfsX6,
1483 10 Q1483H,
1494 12
1489 4 E1489D,