Identification of the patient mutations in genomic DNA. (A) A genomic DNA fragment of 442 bp comprising exons 5 to 7 of GPIIb was PCR-amplified, digested with Taq I, denatured, and used to search for mutations by SSCP analysis, using a 16% acrylamide-8.7% glycerol gel at 14°C. (B) A 193-bp genomic DNA fragment comprising exon 21 of GPIIb was subjected to SSCP analysis in a 14% acrylamide-8.7% glycerol gel at 15°C. The arrows point to distinct bands shown by the patient and her father or mother, respectively. (C) and (D) show fragments of the sequencing ladders of the sense strands (5′ at the bottom). The arrows point to a heterozygous C to A transversion at position +2 of exon 5-intron 5 boundary of GPIIb (C) and a T to C transition in exon 21 of GPIIb (D).