TFAP2B and Char syndrome: Mutations in another transcription factor gene – TFAP2B – expressed in neural crest cells were shown to be responsible for a phenotypically distinct autosomal dominant disorder, Char syndrome (MIM 169100) characterized by patent ductus arteriosus, fifth digit middle phalangeal hypoplasia, and additional facial dysmorphism (Char, 1978; Satoda et al., 2000).