Sequencing analysis of the

Chk2 gene. (A) Direct sequencing of the message of patient 1375's leukemia cells showed a 7-bp insertion between exons 10 and 11 (left). Sequencing of the Chk2 exon 11–F/R–amplified PCR products of patient 1375's DNAs revealed that a A>G nucleotide change in the consensus splice-acceptor site of intron 10 was only shown in leukemia DNA (center) but not in germ-line DNA from patient 1375's skin (right). (B) Patient 154 showed a 15-bp deletion between codons 75 and 79 of Chk2 (upper) and wild-type sequence of Chk2 (lower).