KCNQ1 Variant T224M

Summary of observed carriers, functional annotations, and structural context for KCNQ1 T224M. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT1 penetrance

39%

39/100 effective observations

Total carriers

90

35 LQT1 · 55 unaffected

Functional studies

0

Publications with functional data

T224M is present in 1 alleles in gnomAD. This residue resides in a Hotspot region for LQT1.

Variant features alone are equivalent to phenotyping 4 individuals with LQT1 and 6 unaffected individuals.

In silico predictors

Variant-level computational predictors.
PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density LQT1 (%)
-4.67 1.0 -1 0.948 45

PROVEAN scores below -2 suggest deleterious impact. REVEL scores above 0.5–0.75 are often interpreted as likely pathogenic. PolyPhen-2 scores above 0.85 are typically pathogenic. BLAST-PSSM reflects evolutionary conservation; more negative values indicate rarer substitutions. Penetrance density summarises neighbouring residue risk (Kroncke et al. 2019).

Reported carrier data

Observed carriers by publication or cohort.
Source Year Carriers Unaffected LQT1 Other Disease
33141630 2020 88 54 34 None
32470535 2020 None None None None
Literature, cohort, and gnomAD 90 55 35
Variant features alone 15 6 4

Totals may differ from individual publications due to duplicate patients removed during curation.

Nearby variants

Neighbouring residues within 15 Ångström provide structural context. Variants listed in the right-most column have been observed clinically or in gnomAD.

Previously observed variants near T224M.
Neighbour residue Distance (Å) Observed variants
224 0 T224M,
223 4
225 4 S225L, S225del,
221 5
228 6
227 6
220 6 Q220K,
226 7 A226V,
222 7
219 8 G219E,
229 9 G229D,
212 9
215 10 V215M, V215G, V215L, V215L,
230 11
211 11
216 11 G216R,
231 11 R231C, R231H, R231S,
282 12 L282P,
217 12
208 12 A208V,
285 13
218 13
213 13
232 13
286 13
233 14 L233P,
209 14 S209P,
214 14 C214Y,
278 14 Y278H,
283 15 A283G, A283T,
281 15 Y281C