A G-to-A mutation was introduced into exon 15, changing arginine codon 528 (CGC) to a histidine codon (CAC), and an FRT site flanked puromycin resistance gene cassette was inserted into intron 15. The puro cassette was removed through subsequent flp-mediated recombination. The mutation is found in familial hyperkalemic hypertension (FHHt) patients. (J:306924)