Restriction analysis for confirmation of the exon 9 mutations. In all gels, the Std. lane contained the size standards generated by HaeIII digestion of ▹X174, (Pharmacia, Piscataway, NJ). (A) HinP1I restriction of exon 9 PCR products from the family 6 proband and other family members with the R411C mutation. (B) Elimination of a BanII restriction site confirms the presence of the R448Q mutation in members of family 7. (C)BsrI restriction of the PCR product from exon 9 of the family 9 proband (lane 3) confirmed the presence of the R452C mutation. The 2 normal controls (lanes 2 and 4) remained uncut.