KCNQ1 Variant V211A Detail

We estimate the penetrance of LQTS for KCNQ1 V211A is 21%. We are unaware of any observations of this variant in individuals. V211A is not present in gnomAD. V211A has not been functionally characterized. This residue is located in a Mild_Hotspot region for LQT1. In silico predictions, functional data (if available), and location in structure are equivalent to observing 2 individuals with LQT1 and 8 unaffected individuals. These data combined with observations of carriers lead us to estimate the LQTS penetrance for KCNQ1 V211A around 21% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-3.18 0.113 0 0.711 26
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 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 LQT1 Other Disease
LITERATURE, COHORT, AND GNOMAD: - 0 0 0
VARIANT FEATURES ALONE: - 10 8 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.

V211A has 38 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. NOTE: some residues appear multiple times at different distances. This results from the fact that the functional KV7.1 channel is a homotetramer and occasionally the same residue from multiple subunits is present within the 15A window. 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
211 0
212 4
210 5 M210I, M210I, M210I,
208 5 A208V,
214 5 C214Y,
209 6 S209P,
207 6 V207M, V207L, V207L, V207L, V207L, V207del,
213 7
215 7 V215M, V215G, V215L, V215L,
221 7
225 8 S225L, S225del,
216 9 G216R,
226 9 A226V,
206 9 V206L,
222 10
230 10
229 10 G229D,
205 10 V205M,
233 11 L233P,
219 11 G219E,
164 11
204 11 I204M, I204F,
224 11 T224M,
161 11
220 12 Q220K,
160 12 E160del, E160K, E160V,
223 12
203 12 L203P,
217 12
157 13 F157C,
227 13
228 13
232 14
165 14 V165M,
218 14
237 14
234 14 Q234H, Q234H,
168 15 G168R, G168R, G168R, G168R,