KCNH2 Variant Browser

Below is a comprehensive list of variants found in KCNH2 affected or unaffected with the disease most commonly associated with variants in KCNH2: long QT type 2 (LQT2; OMIM: 613688). Coding variants are referenced to isoform "A" (Q12809-1, transcript ENST00000262186.10) to match convention. Our analysis is primarily for missense and in-frame insertion/deletion variants; however, some nonsense variants are included. We do not include synonymous variants. 'LQT2' is the number of heterozygotes diagnosed with LQT2; 'Unaffected' is the number of heterozygotes unaffected with disease, including those found in the genome aggregation database (gnomAD). Multiplexed assay of variant effect (MAVE) data demonstrate concentration of the potassium channel at the cell surface, done in very high throughput, referenced to WT (100%), PMID: 39315434. Click variant link for more details. Below are histogram plots for LQT2 affected carriers, unaffected carriers, and estimated LQT2 penetrance. Use the 'Search Builder' and 'Search Panes' to select subsets of variants based on properties you are interested in (results will update the histogram plots below).

Histogram of KCNH2 Variant Carriers with LQTS

Below is histogram of the number of heterozygous carriers of KCNH2 variants observed in individuals diagnosed with LQT2 displayed in the table above. The y-axis is the number of unique variants and the x-axis shows the number of heterozygous carriers.

Histogram of Putative Unaffected Heterozygous KCNH2 Variant Carriers

Below is a histogram of the number of heterozygous carriers of KCNH2 variants observed in unaffected individuals and in gnomAD (given the rarity of the LQT2 phenotype in the general public, we assume these individuals are also likely unaffected) displayed in the table above. The y-axis is the number of unique variants (log scale) and the x-axis shows the number of heterozygous carriers (truncated at 300 to aid visualization).

Histogram of LQT2 Penetrance Estimates for KCNH2 Variants

Below is a histogram of the estimates of LQT2 penetrance for all variants displayed in the table above. The range is from 0% (impossible) to 100% (certain).