SCN5A Variant C139Y Detail

We estimate the penetrance of LQTS for SCN5A C139Y around 3% and the Brugada syndrome penetrance around 40%. SCN5A C139Y was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. C139Y is not present in gnomAD. C139Y has been functionally characterized in 0 papers. This residue is located in a 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 (4 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 C139Y around 3% (0/10) and the Brugada syndrome penetrance around 40% (4/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.75 59 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 11 0 4 - -
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.

C139Y has 37 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 12 c.692_693delCA,
147 13
131 12
164 10 F164L,
130 14
170 15 F170I,
228 12 K228R,
138 5 M138I,
227 15 L227P,
171 13
143 6
137 6 I137V,
142 5
229 10
163 13 c.486delC,
232 10 V232F, V232I,
133 10
132 10 c.393-5C>A,
160 14 p.V160fs,
134 9 N134S,
226 12 A226G, A226V,
166 15 A166T,
144 10
230 14 I230M, I230V, I230T,
139 0 p.I137_C139dup,
148 14
165 15
146 11 V146M, V146A,
136 5 L136P,
168 11
233 14
141 6 I141V, I141N,
135 7 M135V,
167 11
225 11 R225Q, R225W,
145 10
140 5