Exon 26 was replaced with one containing a deletion of residues QKP 1510-1512 (CAGAAGCCC). In addition, an FRT-flanked neomycin resistance cassette in opposite-orientation was inserted 148 bp upstream of exon 26. Flp-mediated recombination removed the selection cassette resulting in an allele with deletion of the QKP amino acids. This deletion is equivalent to the human QKP1507-1509 deletion in patients with Long QT syndrome. (J:266290)