KCNQ1 Variant F340C

Summary of observed carriers, functional annotations, and structural context for KCNQ1 F340C. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT1 penetrance

64%

6/10 effective observations

Total carriers

0

0 LQT1 · 0 unaffected

Functional studies

0

Publications with functional data

F340C 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 (%)
-7.41 1.0 -3 0.916 69

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
19687231 2009 None None None None
Literature, cohort, and gnomAD – 0 0 0 –
Variant features alone – 15 4 6 –

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 F340C.
Neighbour residue Distance (Å) Observed variants
340 8 F340del, F340L, F340L, F340L, F340S,
337 9
341 9 A341V, A341E,
338 10 S338F,
335 10 F335L, F335L, F335L,
336 10 A336S,
310 11 V310I,
312 11 T312del, T312I,
311 11 T311A, T311I,
339 11 F339del, F339S,
267 11 Y267C
269 12 G269D, G269S, G269del,
342 12 L342F, L342P,
334 12 V334A,
274 12 I274V,
343 12 P343S, P343L, P343R,
333 12
272 12 G272D, G272S, G272V,
344 13 A344V, A344E,
266 13 L266P,
265 13 T265I,
309 13 T309I, T309R,
332 13
307 13 V307L, V307L,
270 13 F270S,
268 13 I268V, I268S,
330 14
273 14 L273F, L273V, L273R,
345 14 G345R, G345R, G345A,
303 14 L303P,
313 14
306 14 G306V, G306R, G306R,
329 14 A329T,
331 14
276 14 S276del,
308 15 V308F,
271 15