Enamel malformations associated with a defined dentin sialophosphoprotein mutation in two families.

[dentinogenesis imperfecta]

Dentin sialophosphoprotein (DSPP ) mutations cause dentin dysplasia type II (DD-II ) and dentinogenesis imperfecta types II and III (DGI -II and DGI -III , respectively ). We identified two kindreds with DGI -II who exhibited vertical bands of hypoplastic enamel . Both families had a previously reported DSPP mutation that segregated with the disease phenotype . Oral photographs and dental radiographs of four affected and one unaffected participant in one family and of the proband in the second family were used to document the dental phenotypes . We aligned the 33 unique allelic DSPP sequences showing variable patterns of insertions and deletions (indels ), generated a merged dentin phosphoprotein (DPP ) sequence that includes sequences from all DSPP length haplotypes , and mapped the known DSPP mutations in this context . Analyses of the DSPP sequence changes and their probable effects on protein expression , as well as published findings of the dental phenotype in Dspp null mice , support the hypothesis that all DSPP mutations cause pathology through dominant-negative effects . Noting that Dspp is transiently expressed by mouse pre-ameloblasts during formation of the dentino-enamel junction , we hypothesize that DSPP dominant-negative effects potentially cause cellular pathology in pre-ameloblasts that , in turn , causes enamel defects . We conclude that enamel defects can be part of the dental phenotype caused by DSPP mutations , although DSPP is not critical for dental enamel formation .

Diseases
Validation

Diseases presenting "dentin dysplasia" symptom

dentin dysplasia

dentinogenesis imperfecta

oligodontia

This symptom has already been validated