Figure 1.

Pedigrees and proband's phenotype in families with DSPP −1 frameshifts. (A) Family 1: the four generation pedigree of a family diagnosed with dentin dysplasia type II following an autosomal dominant pattern of inheritance. The dental phenotype was mild, with grayish/yellowish discoloration of the permanent dentition. The panorex radiograph showed premature obliteration of the root canals, thistle‐shaped pulp chambers, and mildly bulbous molar crowns. The cause of this phenotype was confirmed by SMRT sequencing to be c.3135delC; p.Ser1045Argfs*269. This designation is, by convention, numbered as if the deletion had occurred in the DSPP reference sequence (NM_014208.3). (B) Family 2: the pedigree is consistent with an autosomal dominant pattern of inheritance. The proband presented with a more severe dental phenotype than the proband of Family 1, with grayish discoloration of the crowns, bulbous crown morphology with constricted cervical areas of the roots, and obliterated pulp chambers and root canals. This phenotype was caused by a five nucleotide duplication in a single DSPP allele with haplotype SHap3 (c.3504_3508dup; p.Asp1170Alafs*146) that would have produced a −1 frameshift that is known to cause inherited dentin defects. An asterisk in the pedigree marks persons who were recruited for the study and contributed DNA samples. DSPP, dentin sialophosphoprotein; SMRT, single molecule real time.