Figure 3 (A) Sequencing chromatogram of the mutation c.2590 G→A in IV:6. The affected person is heterozygous for the missense mutation E864K and the G→A substitution is denoted by an "R". (B) The mutation segregates with sensorineural hearing loss in family #148. The 783 bp PCR product digested by Bsp1286I presents a 246 bp fragment (69 plus 177 bp) in heterozygotes in addition to the wild type fragments (69, 177, 218, and 319 bp) after separation in 2% agarose gel. Roman numbers above the gel refer to the family pedigree (fig 1). M is the DNA ladder (150, 200, 250, 300 and 400 bp) (C) Alignment of the 11 amino acid codons around the E864K mutation demonstrate conservation of the protein sequence and redundancy in the DNA sequence (sequence data: UCSC Genome Browser;³⁴ (a) Homo sapiens chr4:6368639–6368671, NCBI build 34 July 2003; (b) Mus musculus chr5:35260341–35260373, NCBI build 30 February 2003; (c) Rattus norvegicus chr14:79406244–79406276, HGSC version3.1, Jun 2003; (d) Pan troglodytes chr3:6485955–6485987, NCBI build 1, version 1, November 2003, (e) Gallus gallus chr4:79834614–79834646, galGal, February 2004).