KCNQ1 Variant A149T

Summary of observed carriers, functional annotations, and structural context for KCNQ1 A149T. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT1 penetrance

42%

4/10 effective observations

Total carriers

0 LQT1 · 0 unaffected

Functional studies

Publications with functional data

A149T has not been reported 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 (%)
-0.37	0.004	0	0.528	48

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
Literature, cohort, and gnomAD	–	0	0	0	–
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 A149T.
Neighbour residue	Distance (Å)	Observed variants
149	0
150	4	A150T,
152	5
153	5	T153M,
143	5	S143F, S143P, S143Y,
151	6
146	6	E146K, E146G, E146Q,
148	6
147	7	Q147R,
145	8
142	8
144	8	T144A
154	8
155	9
156	9
140	10	S140G, S140R, S140R, S140R,
139	10
141	11	V141M,
157	12	F157C,
227	12
231	12	R231C, R231H, R231S,
217	13
298	13	S298I, S298N,
138	13
222	14
159	14	M159del,
136	14
226	14	A226V,
297	14	G297S, G297D, G297R,
230	14
160	14	E160del, E160K, E160V,
299	15