Figure 2. Genotype and phenotypes of AI families. Panels A through I are from family 1 (p.M1T): oral photograph of the proband (A); the pedigree (B); bitewing radiographs of the proband, showing the very thin enamel layer that is evident only radiographically on the cusp tips (C,D); DNA sequencing chromatograms (E–H) of exon 2 from an affected male member (IV-2) showing the mutation (Mut) that changed the ATG of the wild-type (Wt) start codon into an ACG, which is normally a threonine codon; and single-stranded conformational polymorphism (SSCP) analysis of exon 2, with arrowheads pointing to the extra band that correlates with affection status (I). Panels J through P are from family 2 (p.W4S): oral photographs of the proband (J, III-2) and her mother (K, II-2), who were both affected; the pedigree of family 2 (L); and DNA sequencing chromatograms from the proband, showing the mutation in the fourth codon of exon 2 (M-P), which changed the wild-type tryptophan codon (TGG) into a serine (TCG) codon.