SCN5A Variant P1725L Detail

We estimate the penetrance of LQTS for SCN5A P1725L around 6% and the Brugada syndrome penetrance around 23%. SCN5A P1725L was found in a total of 6 carriers in 1 papers and/or in gnomAD: 1 had Brugada syndrome, 0 had LQTS. P1725L is present in 5 alleles in gnomAD. P1725L has been functionally characterized in 1 papers. This residue is located in a 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 (2 diagnosed with Brugada syndrome) and 5 individuals for LQTS (0 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A P1725L around 6% (0/16) and the Brugada syndrome penetrance around 23% (3/16).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-8.04 0.999 -2.9 0.916 29 10
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
26173111 2015 1 0 1 0
LITERATURE, COHORT, AND GNOMAD: - 6 5 0 1 -
VARIANT FEATURES ALONE: - 15 13 0 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.

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)
26173111 2015

P1725L 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
1403 15
1746 14 A1746T, A1746V,
1724 3
1741 15 D1741E, D1741N, D1741Y,
1726 4
1745 11
1397 11 c.4190delA, c.4189delT,
1743 11 G1743R, G1743E,
1723 5 T1723N,
1725 0 P1725L,
1398 13 V1398M,
1396 13
1744 13 S1744I,
1721 11
1742 12
1727 6
1719 14
1731 11
1728 5 C1728R, C1728Y, C1728W,
1401 14
1399 11
1730 11 P1730H, P1730A, P1730L,
1683 14
1400 15 V1400I,
1718 13 S1718R,
1722 7 N1722D,
1729 8 D1729N,
1720 14 c.5157delC,
1685 15