We estimate the penetrance of LQTS for KCNH2 G262fsX is %. This variant was found in a total of 2 carriers in 3 papers or gnomAD (version 4), 2 had LQTS. G262fsX is not present in gnomAD. G262fsX has not been functionally characterized. This residue is located in a None region for LQT2.

PROVEAN	PolyPhen-2	BLAST-PSSM	REVEL	Penetrance Density (%)
None	None	None	None

PROVEAN scores less than -2 are considered deleterious. REVEL scores higher than 0.5 or 0.75 are considered likely pathogenic (higher sensitivity with the former cutoff, higher specificity with the latter cutoff). A PolyPhen-2 score of 0.85 or greater is considered likely pathogenic. BLAST-PSSM reflects the evolutionary conservation of residue substitutions, more negative numbers indicate fewer observations of the specific substitution than is expected. Penetrance density is our previously published method to calculate the average LQTS probability density in a shell of residues surrounding a residue of interest (Kroncke et al. 2019).

PubMed ID	Year	Carriers	Unaffected	LQT2	Other Disease
24667783	2015	1	0	1
Italy Cohort	2020	6	3	3
25935074	2015	1	0	1
LITERATURE, COHORT, AND GNOMAD:	-	2	0	2	-
VARIANT FEATURES ALONE:	-	10	NA	NA	-

Summary totals might not agree with the literature table because of duplicate patients, which were excluded from the total counts. We do not distinguish here between multiple missense codons. Missense variants are combined across degenerate codon substitutions since codon-level data were not consistently available for curation.