(a) RFLP of the BbsI-digested PCR fragments flanking the 1235T>C region for the family affected by LFSNHL and one normal control. The 672-bp PCR product obtained using the forward primer (5'-TTC CCA CGT ACC ATC TTT CC-3') and the reverse primer (5'-CAC ATC CAG GTT GGG CTC-3') contains a polymorphic restriction site at position 1235. Two fragments of 455 bp and 217 bp from genotype TT were unaffected by enzyme digestion, while three fragments of 672 bp (solid arrow), 455 bp, and 217 bp were observed from heterozygotes carrying genotype TC as I:2, II:1, II:3 and one normal control (C indicated by the open arrow). M: DNA marker. (b) RFLP of NlaIII digested the fragment flanking the 2005T>C region of LFSNHL family members and normal controls. The 154-bp PCR product of the polymorphic restriction site at position 2005 was amplified by PCR using the forward primer (5'-GTC AAG CTC ATC CTG GTG TG-3') and reverse primer (5'-CCA TGT TGG TCT CCT TCC AG-3'). Genotype TT such as unaffected individuals and controls (C1, C2, C3 and C4) demonstrated two fragments of 78 and 75 bp, whereas the heterozygote TC such as I:2, II:1, and II:3 showed 4 fragments of 78, 75, 41 (solid arrow), and 37 bp (solid arrow). In all samples, the enzyme also generated a fragment of 1 bp, which was too small to be seen in the gel. U: undigested control, M: DNA marker. (c) Electrophoregrams of WFS1 gene sequences flanking position 2005 of the affected and unaffected family members. The affected family members are heterozygote (T and C) in position 2005 (labeled with a star), while the unaffected family members are homozygous as T in the same place.