KCNQ1 Variant L347R

Summary of observed carriers, functional annotations, and structural context for KCNQ1 L347R. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT1 penetrance

70%

7/11 effective observations

Total carriers

1

0 LQT1 · 1 unaffected

Functional studies

0

Publications with functional data

L347R has not been reported in gnomAD. This residue resides in a Hotspot region for LQT1.

Variant features alone are equivalent to phenotyping 7 individuals with LQT1 and 3 unaffected individuals.

In silico predictors

Variant-level computational predictors.
PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density LQT1 (%)
-5.34 1.0 -4 0.904 80

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
33082985 2020 1 1 None None
30758498 2019 1 None None None
Literature, cohort, and gnomAD – 1 1 0 –
Variant features alone – 15 3 7 –

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 L347R.
Neighbour residue Distance (Å) Observed variants
348 8
345 9 G345R, G345R, G345A,
349 9 S349W,
347 9 L347P, L347R,
344 10 A344V, A344E,
352 10
351 10 F351L, F351L, F351L, F351S,
350 11 G350V, G350R, G350R, G350W,
346 11
343 12 P343S, P343L, P343R,
353 12 L353P,
266 13 L266P,
342 13 L342F, L342P,
254 13 V254M, V254L, V254L,
264 13
341 13 A341V, A341E,
263 13
260 13
250 13 L250H, L250P,
259 14 R259C, R259H, R259L, R259G
258 14 H258P, H258N, H258R, H258Y,
355 14
251 14 L251P, L251Q,
255 14
354 14
256 14
262 15 L262P, L262R, L262V,