KCNQ1 Variant V129D Detail

We estimate the penetrance of LQTS for KCNQ1 V129D is 29%. We are unaware of any observations of this variant in individuals. V129D is not present in gnomAD. V129D 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 V129D around 29% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-4.93 0.956 -3 0.896 31
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.

V129D has 54 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
129 0 V129I,
128 4 A128del,
132 5 I132L,
130 6
126 6 H126D,
125 6
131 6
133 6 V133I,
127 7 F127L, F127L, F127L,
167 8
166 8 F166V,
241 8 V241F, V241I, V241G,
124 9
134 9 L134P,
163 9
240 9 H240R, H240P,
170 9
237 10
123 10
135 10
238 11 M238V, M238L, M238L,
136 11
243 11 R243H, R243C, R243P, R243S,
114 11
122 11 C122Y,
113 11
159 12 M159del,
137 12 L137F, L137P,
174 12 R174H, R174C, R174L,
239 12
162 12 V162M,
164 12
202 13 D202N, D202H,
168 13 G168R, G168R, G168R, G168R,
242 13 D242N, D242Y,
121 13
234 13 Q234H, Q234H,
169 13 T169M, T169R,
117 13 P117L,
165 13 V165M,
160 13 E160del, E160K, E160V,
115 13 E115A, E115G,
120 14 W120C, W120C,
236 14 L236Q, L236R,
205 14 V205M,
138 14
235 14 I235N,
171 15
139 15
119 15 G119R, G119V,
198 15 I198V, I198T,
173 15
267 15 Y267C,
206 15 V206L,