(a) Plasminogen exon 15 sequence analysis in family 2 (noncoding strand is shown). Single-stranded DNA fragments with a variant migration pattern in SSCP analysis (Fig 3, bands a, b, and c) were excised from polyacrylamide gel and sequenced as described in Materials and Methods. The DNA of the patient 2 (band a in Fig 3) exhibited a homozygous point mutation (G → A) at position 1924, leading to a stop codon at position 597 (Trp₅₉₇ → STOP). The mother and the father (Fig 3, I-1 and I-2) are heterozygous for this mutation. Numbering of nucleotides and amino acids is rendered according to Forsgren et al52 and Petersen et al,21 respectively. (b) The second allele of the father (band b) contained a point mutation (G → C) at position 1924, leading to an amino acid exchange (Trp₅₉₇ → Cys₅₉₇ ). Numbering of nucleotides and amino acids is rendered according to Forsgren et al52 and Petersen et al,21 respectively.