SCN5A Variant K228R Detail

We estimate the penetrance of LQTS for SCN5A K228R around 10% and the Brugada syndrome penetrance around 9%. SCN5A K228R was found in a total of 1 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. K228R is present in 1 alleles in gnomAD. K228R 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 (0 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 K228R around 10% (0/11) and the Brugada syndrome penetrance around 9% (0/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-2.93 0.993 6.54 0.843 12 4
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 15 0 0 - -
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.

K228R has 58 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 10 I848F,
223 11 V223L,
240 12 V240M,
231 6 c.692_693delCA,
198 12
131 15
193 7 W193R, W193X,
164 15 F164L,
195 12
237 13
228 0 K228R,
138 7 M138I,
227 6 L227P,
143 14
171 11
137 9 I137V,
234 14 P234S,
142 10
197 7
229 6
851 13 c.2552_2553dupGT, F851L, c.2550_2551dupGT, p.F851CfsX19,
221 15
196 8
852 12
222 14 R222L, R222X, R222Q,
224 9 L224F,
845 12 c.2533delG,
232 8 V232F, V232I,
133 13
191 12
134 10 N134S,
849 13
226 6 A226G, A226V,
235 14 G235R, c.704-1G>C, c.703+1G>A,
144 12
172 14
230 7 I230M, I230T, I230V,
199 12 S199T,
139 12 p.I137_C139dup,
236 11
847 15
192 11
136 13 L136P,
168 11
175 12 K175N,
233 11
194 9
141 7 I141V, I141N,
188 14
135 12 M135V,
167 14
128 14 c.381dupT,
201 12
225 6 R225Q, R225W,
844 14 L844RfsX3,
200 11
145 12
140 11