Method of diagnosing and treating dentinogenesis imperfecta type II by using dentin sialophosphoprotein gene and coded product thereof

A method for determining the susceptibility of dentinogenesis imperfecta type II (DGI-II) and/or DGI-II with deafness in a human subject comprising the steps of:

• detecting the dentin sialophosphoprotein (DSPP) gene or transcript in said subject and comparing it with the wild-type DSPP gene or transcript thereof to determine whether there is any difference between the DSPP gene or transcript in said subject and the wild-type DSPP gene or transcript, wherein the wild-type gene comprises a nucleotide sequence of SEQ ID NO:1 and the wild-type transcript comprises nucleotides 7-98, 2359-2437, 3577-3660, 3794-4780, and 5257-8201 of SEQ ID NO:
• 1,
• wherein said difference comprises a G→T mutation at position 1 of Exon 3 or a G→A mutation at position 1 of Intron 3, and wherein said G→T mutation at position 1 of Exon 3 indicates an increased likelihood of suffering DGI-II in said subject and said G→A mutation at position 1 of Intron 3 indicates an increased likelihood of suffering DGI-II with deafness in said subject.