A 6955C to T mutation was introduced into the locus, creating a stop codon in exon 34 and leading to a Q2319X amino acid change with a truncated protein of 2318 amino acids. In addition a loxP flanked PGK-neo cassette was inserted about 400 nucleotides upstream of exon 34 which was removed via cre-mediated recombination. This mutation corresponds to the 6949C to T mutation in the human gene in Hajdu Cheney Syndrome. qRT-PCR confirmed expression of mutant RNA transcript. (J:230045)