Genetic Linkage of the Dentinogenesis Imperf ecta Type III Locus to Chromosome 4q

M. MacDougall, L. G. Jeffords, T. T. Gu, C. B. Knight, G. Frei, B. E. Reus, B. Otterud, M. Leppert, R. J. Leach

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27 Scopus citations


Dentinogenesis imperfecta type III (DGI-III) is an autosomal-dominant disorder of dentin formation which appears in a tri-racial southern Maryland population known as the "Brandywine isolate". This disease has suggestive evidence of linkage to the long arm of human chromosome 4 (LOD score of 2.0) in a family presenting with both juvenile periodontitis and DGI-III. The purpose of this study was to screen a family presenting with only DGI-III to determine if this locus was indeed on chromosome 4q. Furthermore, we wanted to determine if DGI-III co-localized with dentinogenesis imperfecta type II (DGI-II), which has been localized to 4q21-q23. Therefore, a large kindred from the Brandywine isolate was identified, oral examination performed, and blood samples collected from 21 family members. DNA from this family was genotyped with 6 highly polymorphic markers that span the DGI-II critical region of chromosome 4q. Analysis of the data yielded a maximum two-point LOD score of 4.87 with a marker for the dentin matrix protein l (DMP1) locus, a gene contained in the critical region for DGI-II. Our results demonstrated that the DGI-III locus is on human chromosome 4q21 within a 6.6 cM region that overlaps the DGI-II critical region. These results are consistent with the hypothesis that DGI-II is either an allelic variant of DGI-III or the result of mutations in two tightly linked genes.

Original languageEnglish (US)
Pages (from-to)1277-1282
Number of pages6
JournalJournal of dental research
Issue number6
StatePublished - 1999


  • Chromosome 4q
  • Dentin dysplasia
  • Dentin matrix protein 1
  • Dentinogenesis imperfecta
  • Linkage

ASJC Scopus subject areas

  • General Dentistry


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