Sequence analysis of p67-phox cDNA in patient IP. The region between exons 2 and 5 was amplified by PCR using primers p67-94LcDNA and p67-455RcDNA. The upper panel shows the sequences of the patient and control with the 5′ end of the cDNA sequence at the top. The dashed line indicates the beginning of exon 5, the point at which the cDNA sequence returns to normal after the 3 abnormal types of splicing (splice versions labeled II, III, and IV). The lower panel shows a diagram of the different cDNA molecules derived from the alternative splicing. The GT dinucleotide in the 3′ end of exon 4 in the normal cDNA species (version I) is the cryptic splice site used for generating the abnormally spliced version II (exon 4*).