Pedigree and sequence electropherogram. Partial sequences of SALL1 show a nonsense mutation, c.814C>T (p.Q272*) on exon 2, as indicated in red, causing premature termination of the SALL1 protein in the mother (patient 2, II: 5) and son (patient 1, III: 1). The pedigree shows the co-segregation of this mutation with Townes-Brocks syndrome phenotypes.