Concurrent manifestation of oligodontia and thrombocytopenia caused by a contiguous gene deletion in 12p13.2: A three-generation clinical report

Background: Wnt and Wnt-associated pathways play an important role in the genetic etiology of oligodontia, a severe form of tooth agenesis. Loss-of-function mutations in LRP6, encoding a transmembrane cell-surface protein that functions as a coreceptor in the canonical Wnt/b-catenin signaling cascade, also contribute to genetic oligodontia. Methods and results: We describe a three-generation family with hereditary thrombocytopenia and oligodontia. Genome wide array analysis was performed. The array results from the index patient revealed an interstitial loss of 150 kb in 8p23.1 (chr8:6,270,299–6,422,558; hg19) encompassing MCPH1 and ANGPT2 and an interstitial loss of 290 kb in 12p13.2 (chr12:12,005,720–12,295,290; hg19) encompassing ETV6, BCL2L14 and LRP6. Conclusion: This case report shows a three-generation family with hereditary thrombocytopenia and oligodontia with a heterozygous 290 kb novel contiguous gene deletion in band p13.2 of chromosome 12, encompassing LRP6 and ETV6. In this report we discuss the clinical relevance of the deletion of both genes and illustrate the importance of thorough examination of oligodontia patients. Comprising not only the oral status but also the medical history of the patients and their relatives.