SCN5A Variant L142P Detail

We estimate the penetrance of LQTS for SCN5A L142P around 4% and the Brugada syndrome penetrance around 15%. SCN5A L142P was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L142P is not present in gnomAD. L142P has been functionally characterized in 0 papers. This residue is located in a Mild_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 (1 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 L142P around 4% (0/10) and the Brugada syndrome penetrance around 15% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.98 13 0
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 14 0 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.

L142P has 47 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
848 11 I848F,
223 12 V223L,
231 11 c.692_693delCA,
149 12
147 11
164 11 F164L,
228 10 K228R,
138 6 M138I,
227 12 L227P,
171 15
143 5
137 9 I137V,
142 0
197 15
229 7
163 15 c.486delC,
851 11 c.2552_2553dupGT, c.2550_2551dupGT, F851L, p.F851CfsX19,
852 13
222 14 R222Q, R222L, R222X,
224 14 L224F,
845 14 c.2533delG,
150 13
232 10 V232I, V232F,
133 14
132 15 c.393-5C>A,
160 14 p.V160fs,
134 13 N134S,
226 8 A226V, A226G,
144 7
855 14
230 11 I230M, I230V, I230T,
139 5 p.I137_C139dup,
148 10
884 15
146 7 V146A, V146M,
847 13
136 10 L136P,
168 12
233 12
141 5 I141N, I141V,
135 11 M135V,
167 13
225 10 R225Q, R225W,
151 15
844 12 L844RfsX3,
145 5
140 7