KCNQ1 Variant V162A Detail

We estimate the penetrance of LQTS for KCNQ1 V162A is 26%. We are unaware of any observations of this variant in individuals. V162A is not present in gnomAD. V162A 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 V162A around 26% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-2.61 0.995 1 0.882 30
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.

V162A has 40 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
162 0 V162M,
163 4
161 5
165 5 V165M,
158 5
159 6 M159del,
164 6
160 7 E160del, E160K, E160V,
166 7 F166V,
167 9
157 9 F157C,
156 10
213 10
168 10 G168R, G168R, G168R, G168R,
132 11 I132L,
169 11 T169M, T169R,
155 11
209 11 S209P,
136 11
154 12
206 12 V206L,
237 12
129 12 V129I,
210 13 M210I, M210I, M210I,
170 13
133 13 V133I,
234 13 Q234H, Q234H,
135 13
214 13 C214Y,
230 14
139 14
205 14 V205M,
212 14
216 14 G216R,
233 14 L233P,
128 14 A128del,
152 15
153 15 T153M,
208 15 A208V,
125 15