SCN5A Variant H184R Detail

We estimate the penetrance of LQTS for SCN5A H184R around 1% and the Brugada syndrome penetrance around 13%. SCN5A H184R was found in a total of 1 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. H184R is present in 1 alleles in gnomAD. H184R 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 H184R around 1% (0/11) and the Brugada syndrome penetrance around 13% (1/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-1.45 0.642 -1.79 0.539 16 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: - 1 1 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.

H184R has 34 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
192 15
175 11 K175N,
197 15
113 7 V113I, V113A,
194 11
188 6
178 8 A178G,
190 10 R190L, R190W, R190G, R190Q,
128 14 c.381dupT,
179 6 R179X, R179Q,
177 10 L177P,
189 10
121 11 R121Q, R121W,
198 12
124 14 A124D,
118 14
125 13 V125L,
181 8
176 8
172 13
174 13 V174I,
185 5 A185T, A185V,
115 11 S115G,
186 8
182 7 C182R, C182Y,
173 13
112 7 Y112C,
114 7
184 0 H184R,
191 11
116 12
187 5 T187S, T187I,
180 4 G180V,
183 5