KCNQ1 Variant V141M Detail

We estimate the penetrance of LQTS for KCNQ1 V141M is 18%. This variant was found in a total of 6 carriers in 9 papers or gnomAD, 0 had LQTS. V141M is not present in gnomAD. V141M has been functionally characterized in 2 papers. 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 V141M around 18% (2/16).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-2.7 1.0 0 0.906 33
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
30337886 2018 None None None None
29213224 2017 None None None None
28491547 2015 3 3 None SQTS + DCM + AF + AF w/RVR
28383569 2017 None None None None
26279191 2016 1 1 None SQTS, AF, neonatal sinus bradycardia, ventricular pacemaker
25974115 2015 2 2 None SQTS in 1
24818999 2014 2 2 None None
22250012 2012 None None None None
16109388 2005 1 1 None 1 AF
LITERATURE, COHORT, AND GNOMAD: - 6 6 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.

Functional Data Homozygously Collected

Peak current is relative to wildtype (100% being no different from wildtype). V0.5 activation is the voltages at which half of the maximal current is reached during an activation in units of mV and relative to wildtype. Recovery from inactivation (Rec. inact.) and deactivation time (Deactivation) are the ratio of characteristic time constants with wildtype (unitless).

PubMed ID Cell Type Peak Current IKs (%WT) V1/2 Act. Activation time (%WT) Deactivation time (%WT)
16109388 Xeno 300 0.0 None None
22250012 CHO 100 -15.1 1.3 27.95833333

Functional Data Heterozygously Collected

Functional parameters are the same as defined above.

PubMed ID Cell Type Peak Current IKs (%WT) V1/2 Act. Activation time (%WT) Deactivation time (%WT)
16109388 Xeno 160 None None None
22250012 CHO None None None

V141M has 61 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
141 0 V141M,
140 4 S140G, S140R, S140R, S140R,
142 4
144 5 T144A,
299 6
143 6 S143F, S143P, S143Y,
138 6
145 6
300 7 A300T, A300S,
137 7 L137F, L137P,
139 7
298 8 S298I, S298N,
231 8 R231C, R231H, R231S,
303 8 L303P,
148 9
136 9
234 10 Q234H, Q234H,
281 10 Y281C,
301 10
302 10 A302V, A302E, A302T,
135 10
152 10
297 11 G297S, G297D, G297R,
149 11
147 11 Q147R,
156 11
274 11 I274V,
277 11 S277L, S277del, S277P, S277W,
146 11 E146K, E146G, E146Q,
235 11 I235N,
134 11 L134P,
278 12 Y278H,
230 12
323 12
133 13 V133I,
153 13 T153M,
227 13
327 13 T327A, T327S, T327S,
296 13 F296S, F296L, F296L, F296L,
285 13
155 13
238 14 M238V, M238L, M238L,
304 14 W304R, W304R,
229 14 G229D,
273 14 L273F, L273V, L273R,
232 14
151 14
275 14 F275del,
159 14 M159del,
150 14 A150T,
280 14 V280A, V280E,
228 14
160 14 E160del, E160K, E160V,
326 14
237 14
282 14 L282P,
233 14 L233P,
306 15 G306V, G306R, G306R,
226 15 A226V,
276 15 S276del,
154 15