title: Clinical and genetic evaluation of a Chinese family with isolated oligodontia.
abstract: OBJECTIVE
  Oligodontia is defined as the congenital absence of 6 or more permanent teeth excluding the third molar. Tooth agenesis may be classified as syndromic/non-syndromic and as familial/sporadic. To date, more than 300 genes have been found to be involved in tooth development, but only a few of these genes, such as MSX1, PAX9 and AXIN2, are related to the condition of non-syndromic oligodontia. The objective of the present work was to investigate the disease-causing gene of non-syndromic oligodontia in a Han Chinese family and analyse the pathogenesis of mutations that result in oligodontia.
  
  
  METHODS
  We examined all individuals of the oligodontia family by clinical and radiographic examinations. Based on the clinical manifestations, the candidate genes MSX, PAX9 and AXIN2 were selected to analyse and screen for mutations.
  
  
  RESULTS
  The clinical evaluation suggested that the family might show non-syndromic oligodontia. DNA sequencing of the MSX1 gene revealed two mutations in the two patients with oligodontia: a heterozygotic silent mutation, c.348C>T (P.Gly116=), in exon 1 and a homozygotic deletion of 11 nucleotides (c.469+56delins GCCGGGTGGGG) in the intron. However, the silent mutation and the deletion mutation were thought to be known polymorphisms (rs34165410 and rs34341187) by bioinformatics analysis. We did not detect any mutations in the PAX9 and AXIN2 genes of oligodontia patients.
  
  
  CONCLUSIONS
  Our finding suggests that identified polymorphisms (c.348C>T and c.469+56delins GCCGGGTGGGG) may be responsible for the oligodontia phenotype in this Chinese family, but the association requires further study.
authors.affiliation: Department of Dentistry, The First People's Hospital of Lianyungang City, 182 Tongguan Road, Lianyungang, Jiangsu Province, China.
authors.forename: Han
authors.initials: H
authors.lastname: Qin
authors.forename: Hong-zhi
authors.initials: HZ
authors.lastname: Xu
authors.forename: Kun
authors.initials: K
authors.lastname: Xuan
mesh_terms: D000848:Anodontia / Q000000981:diagnostic imaging / Q000235:genetics*; D044466:Asian People / Q000235:genetics*; D060466:Axin Protein / Q000235:genetics*; D005260:Female; D006801:Humans; D051957:MSX1 Transcription Factor / Q000235:genetics*; D008297:Male; D009154:Mutation; D051764:PAX9 Transcription Factor / Q000235:genetics*; D010375:Pedigree; D010641:Phenotype; D011110:Polymorphism, Genetic; D011859:Radiography; D017422:Sequence Analysis, DNA
chemical_list: C491761:AXIN2 protein, human; D060466:Axin Protein; D051957:MSX1 Transcription Factor; C484083:MSX1 protein, human; D051764:PAX9 Transcription Factor; C497323:PAX9 protein, human
keywords: AXIN2; Gene mutation; MSX1; Oligodontia; PAX9; Polymorphism