SCN5A Variant R179Q Detail

We estimate the penetrance of LQTS for SCN5A R179Q around 1% and the Brugada syndrome penetrance around 17%. SCN5A R179Q was found in a total of 7 carriers in 1 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. R179Q is present in 7 alleles in gnomAD. R179Q has been functionally characterized in 1 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 (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 R179Q around 1% (0/17) and the Brugada syndrome penetrance around 17% (2/17).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-3.81 0.999 -1.66 0.927 39 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
28704380 2017 1 0 0 1 SUNDS
LITERATURE, COHORT, AND GNOMAD: - 7 7 0 0 -
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)
28704380 2017

R179Q has 46 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
126 12 K126E,
175 7 K175N,
197 14
113 10 V113I, V113A,
129 10
194 11
188 8
178 3 A178G,
190 14 R190L, R190W, R190G, R190Q,
128 8 c.381dupT,
117 14
179 0 R179X, R179Q,
119 14 P119L, P119S,
177 8 L177P,
189 13
123 12 A123G, A123V,
121 7 R121Q, R121W,
198 13
127 12
124 9 A124D,
118 13
125 7 V125L,
181 11
176 7
172 11
174 9 V174I,
185 10 A185T, A185V,
133 14
115 11 S115G,
186 13
130 15
182 12 C182R, C182Y,
173 11
112 9 Y112C,
114 8
184 6 H184R,
191 12
116 10
187 9 T187S, T187I,
180 6 G180V,
134 14 N134S,
170 15 F170I,
120 13
183 11
122 11
171 13