SCN5A Variant p.L729del Detail

We estimate the penetrance of LQTS for SCN5A p.L729del around 7% and the Brugada syndrome penetrance around 48%. SCN5A p.L729del was found in a total of 1 carriers in 3 papers and/or in gnomAD: 1 had Brugada syndrome, 0 had LQTS. p.L729del is not present in gnomAD. p.L729del has been functionally characterized in 3 papers. This residue is located in a Hotspot region for Brugada syndrome and a Non_Hotspot region for LQTS. In silico predictions, functional data (if available), and location in structure are equivalent to phenotyping 10 individuals for Brugada syndrome (4 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 p.L729del around 7% (0/11) and the Brugada syndrome penetrance around 48% (5/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA None 62 7
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
28069705 2017 1 0 0 1 ARVD
22885917 2012 1 0 1 0
30059973 2018 1 1 0 0
LITERATURE, COHORT, AND GNOMAD: - 1 0 0 1 -
VARIANT FEATURES ALONE: - 15 11 0 4 - -
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)
22885917 2012
30059973 2018
28069705 2017

p.L729del has 42 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
723 10 I723V,
758 14 G758E,
811 13 R811G, R811H, c.2435_2436+3delTGGTAinsCGCCT,
733 6 F733L,
745 14
821 14
760 11 p.F760SfsX5,
721 12
812 14 L812Q,
1350 14 I1350T, I1350L,
759 11 I759V, c.2274delG, p.I759FfsX6,
755 11
731 7 T731I,
754 14
726 5
818 12
737 14
720 15
750 15 Q750R,
822 15 W822X, W822C,
749 11
1346 14 L1346I, L1346P,
724 9 T724I,
728 4 V728I,
727 7
735 10 A735E, A735T, A735V,
732 5
734 10 M734V, c.2201dupT,
756 7
814 11 R814Q,
722 10
757 13
817 13 K817E,
752 9 G752R,
815 12
725 7
751 12 V751F, V751I,
736 12 L736P,
730 6 N730K,
753 11
729 0 p.L729del,
748 11 M748I,