The T at position 6272 in exon 34 was deleted. An FRT-flanked PGK/gb2-neomycin cassette was inserted upstream of exon 34 and was removed via flp-mediated recombination. The 6272delT mutation results in a premature stop codon eight nucleotides further downstream (p.Phe2091SerfsX4). This is a Hajdu Cheney Syndrome-associated mutation.