Figure 4. Restriction fragment length polymorphism (RFLP) analysis showing that the abolishment of a BstSF I site cosegregates with affected individuals. The PCR product of exon 4 with flanking sequences includes 429 bp with 2 BstSF I sites (CTACAG and CTGTAG). The unaffected has three fragments (81 bp, 162 bp, and 186 bp) after BstSF I digestion, whereas the affected has four (81 bp, 162 bp, 186 bp, and the crucial 348 bp). Only the affected allele shows the 384bp band. M means DNA ladder marker.