KCNQ1 Variant Q107H Detail

We estimate the penetrance of LQTS for KCNQ1 Q107H is 67%. This variant was found in a total of 1 carriers in 1 papers or gnomAD, 1 had LQTS. Q107H is not present in gnomAD. Q107H has been functionally characterized in 1 papers. This residue is located in a Hotspot region for LQT1. In silico predictions, functional data (if available), and location in structure are equivalent to observing 6 individuals with LQT1 and 4 unaffected individuals. These data combined with observations of carriers lead us to estimate the LQTS penetrance for KCNQ1 Q107H around 67% (7/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-3.54 1.0 3 0.837 69
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
32893267 2020 1 None 1 None
LITERATURE, COHORT, AND GNOMAD: - 1 0 1
VARIANT FEATURES ALONE: - 10 4 6 -
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)
30571187 HEK 36 0.4 None 1.212109631

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)
30571187 HEK None None None

Q107H has 35 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
107 0 Q107H, Q107H,
106 4
110 5 V110I,
108 5 G108S,
177 5 S177F,
180 7
104 7 T104A, T104I,
179 7 G179S,
176 7
109 8 R109C, R109L,
178 8 A178T, A178del,
105 8
111 8 Y111C,
173 8
112 10
114 10
175 11 L175I,
113 11
174 11 R174H, R174C, R174L,
190 11 R190W, R190Q, R190L,
181 11 R181C,
172 12 V172M, V172E,
115 12 E115A, E115G,
184 13 Y184S, Y184C, Y184D, Y184H,
185 13 V185L, V185L, V185M, V185del,
186 13 G186R, G186D,
193 13 F193L, F193L, F193L,
170 13
116 13
182 14
169 14 T169M, T169R,
171 14
122 15 C122Y,
189 15 G189R, G189R, G189E,
117 15 P117L,