KCNQ1 Variant A283T

Summary of observed carriers, functional annotations, and structural context for KCNQ1 A283T. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT1 penetrance

61%

6/11 effective observations

Total carriers

1

0 LQT1 · 1 unaffected

Functional studies

1

Publications with functional data

A283T has not been reported in gnomAD. This residue resides in a Hotspot region for LQT1.

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

In silico predictors

Variant-level computational predictors.
PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density LQT1 (%)
-3.63 0.977 -1 0.852 67

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
23571586 2013 1 1 None None
Literature, cohort, and gnomAD – 1 1 0 –
Variant features alone – 15 4 6 –

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

Functional data

Functional assay results from published electrophysiology studies. HM indicates homomeric channels, HT indicates heteromeric channels.

Homomeric channel data

Published electrophysiology measurements (homomeric).
PubMed ID Year Study Type Assay Temperature Cell Type Result

Heteromeric channel data

Published electrophysiology measurements (heteromeric).
PubMed ID Year Study Type Assay Temperature Cell Type Result

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 A283T.
Neighbour residue Distance (Å) Observed variants
283 0 A283G, A283T,
284 4 E284K,
282 4 L282P,
280 6 V280A, V280E,
322 6 T322M, T322A, T322K,
324 6
325 6 G325R, G325R, G325E, G325W,
285 7
281 7 Y281C
286 7
287 7 A287E, A287T, A287S,
279 8 F279I,
328 8 I328del,
296 8 F296S, F296L, F296L, F296L,
278 9 Y278H,
320 9 P320H, P320A, P320S,
323 9
321 9
327 10 T327A, T327S, T327S,
228 10
277 10 S277L, S277del, S277P, S277W,
295 11
276 11 S276del,
297 11 G297S, G297D, G297R,
329 11 A329T,
288 11
299 12
294 12 V294M,
319 12 V319L, V319L,
231 13 R231C, R231H, R231S,
332 13
289 14
227 14
232 14
275 14 F275del,
331 14
229 14 G229D,
330 14
144 14 T144A,
224 15 T224M,