Figure 3. Mutation analysis of the EDN3 gene in the family. A: Sequencing chromatograms of individuals from the family. Note the homozygous change C>T in both affected individuals IV-2 and IV-3 (marked by arrows). The normal sibling IV-1 is homozygous for the wild-type allele, whereas both parents (III-2 and III-3) and grandmother (II-2) are heterozygous for the change (see double peaks marked by arrows). B: RFLP analysis to show segregation of the mutation. Note affected individuals have only 528 bp fragment due to loss of the Eco72I site, the normal sibling has 345 and 183 bp fragments, and both carrier parents have all the three fragments. C: Conservation of the threonine (T) residue in different orthologs. The threonine residues are shown in bold letters. The number refers to the position of amino acid residue.