SCN5A Variant N134H Detail

We estimate the penetrance of LQTS for SCN5A N134H around 2% and the Brugada syndrome penetrance around 16%. SCN5A N134H was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. N134H is not present in gnomAD. N134H 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 N134H around 2% (0/10) and the Brugada syndrome penetrance around 16% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.435 18 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.

N134H has 43 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
231 10 c.692_693delCA,
198 15
124 12 A124D,
131 5
193 15 W193X, W193R,
130 7
170 12 F170I,
228 10 K228R,
138 7 M138I,
171 9
143 15
137 6 I137V,
142 13
197 12
229 12
129 7
123 15 A123G, A123V,
127 9
125 12 V125L,
232 10 V232I, V232F,
174 11 V174I,
133 4
132 7 c.393-5C>A,
134 0 N134S,
226 15 A226V, A226G,
179 14 R179X, R179Q,
172 13
230 14 I230M, I230V, I230T,
139 9 p.I137_C139dup,
126 13 K126E,
136 7 L136P,
168 12
175 10 K175N,
233 15
194 13
141 11 I141N, I141V,
135 5 M135V,
167 12
178 13 A178G,
128 7 c.381dupT,
225 12 R225Q, R225W,
173 15
140 11