The measurements of KCNQ1 mutants in the homozygous and heterozygous state without KCNE1 may also be of putative future interest, as there are other tissues where KCNQ1 may not co-assemble with its ß-subunits, and thus this information might be valuable in the future, helping the interpretation of putative non-cardiac manifestations in LQTS. This evidence concerns the gene KCNE1 and familial long QT syndrome.