Clinical and genetic evaluation of a Chinese family with isolated oligodontia.

[oligodontia]

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 MSX 1 , PAX 9 and AXIN 2 , 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 .We examined all individuals of the oligodontia family by clinical and radiographic examinations . Based on the clinical manifestations , the candidate genes MSX , PAX 9 and AXIN 2 were selected to analyse and screen for mutations .The clinical evaluation suggested that the family might show non-syndromic oligodontia . DNA sequencing of the MSX 1 gene revealed two mutations in the two patients with oligodontia : a heterozygotic silent mutation , c .348 C >T (P .Gly 116 =), in exon 1 and a homozygotic deletion of 11 nucleotides (c .469 +56 delins GCCGGGTGGGG ) in the intron . However , the silent mutation and the deletion mutation were thought to be known polymorphisms (rs 34165410 and rs 34341187 ) by bioinformatics analysis . We did not detect any mutations in the PAX 9 and AXIN 2 genes of oligodontia patients .Our finding suggests that identified polymorphisms (c .348 C >T and c .469 +56 delins GCCGGGTGGGG ) may be responsible for the oligodontia phenotype in this Chinese family , but the association requires further study .

Diseases
Validation

Diseases presenting "heterozygotic silent mutation" symptom

oligodontia

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