Identification of a novel mutation, g.49C→T/(Pro17Ser), in the DSPP gene in the Chinese family with type II DGI. a. DNA sequences for a normal family member (upper panel) and the proband III-1 (lower panel). The sequence of codon 17 where the mutation occurs is boxed. The C to T change in the proband results in the substitution of a proline residue by a serine residue in the DSP protein. The predicted signal peptide domain covers the first 15 amino acids, MKIITYFCIWAVAWA. The mature protein starts with the next isoleucine (I) residue. b. The alignment of amino acids in the N-terminal domain of DSPP from homo sapiens, sus scrofa, bos taurus, mus musculus, and rattus norvegious revealed that the Pro17 residue was highly conserved during evolution.