@article {466, title = {A biallelic ANTXR1 variant expands the anthrax toxin receptor associated phenotype to tooth agenesis.}, journal = {Am J Med Genet A}, volume = {176}, year = {2018}, month = {2018 04}, pages = {1015-1022}, abstract = {

Tooth development is regulated by multiple genetic pathways, which ultimately drive the complex interactions between the oral epithelium and mesenchyme. Disruptions at any time point during this process may lead to failure of tooth development, also known as tooth agenesis (TA). TA is a common craniofacial abnormality in humans and represents the failure to develop one or more permanent teeth. Many genes and potentially subtle variants in these genes contribute to the TA phenotype. We report the clinical and genetic impact of a rare homozygous ANTXR1 variant (c.1312C>T), identified by whole exome sequencing (WES), in a consanguineous Turkish family with TA. Mutations in ANTXR1 have been associated with GAPO (growth retardation, alopecia, pseudoanodontia, and optic atrophy) syndrome and infantile hemangioma, however no clinical characteristics associated with these conditions were observed in our study family. We detected the expression of Antxr1 in oral and dental tissues of developing mouse embryos, further supporting a role for this gene in tooth development. Our findings implicate ANTXR1 as a candidate gene for isolated TA, suggest the involvement of specific hypomorphic alleles, and expand the previously known ANTXR1-associated phenotypes.

}, keywords = {Alleles, Amino Acid Substitution, Animals, Anodontia, Child, Consanguinity, Facies, Genetic Association Studies, Genotype, Humans, Male, Mice, Mutation, Neoplasm Proteins, Pedigree, Phenotype, Radiography, Receptors, Cell Surface, Whole Exome Sequencing}, issn = {1552-4833}, doi = {10.1002/ajmg.a.38625}, author = {Dinckan, Nuriye and Du, Renqian and Akdemir, Zeynep C and Bayram, Yavuz and Jhangiani, Shalini N and Doddapaneni, Harsha and Hu, Jianhong and Muzny, Donna M and Guven, Yeliz and Aktoren, Oya and Kayserili, H{\"u}lya and Boerwinkle, Eric and Gibbs, Richard A and Posey, Jennifer E and Lupski, James R and Uyguner, Zehra O and Letra, Ariadne} } @article {523, title = {Identification of likely pathogenic and known variants in TSPEAR, LAMB3, BCOR, and WNT10A in four Turkish families with tooth agenesis.}, journal = {Hum Genet}, volume = {137}, year = {2018}, month = {2018 Sep}, pages = {689-703}, abstract = {

Tooth agenesis (TA), the failure of development of one or more permanent teeth, is a common craniofacial abnormality observed in different world populations. The genetic etiology of TA is heterogeneous; more than a dozen genes have been associated with isolated or nonsyndromic TA, and more than 80 genes with syndromic forms. In this study, we applied whole exome sequencing (WES) to identify candidate genes contributing to TA in four Turkish families. Likely pathogenic variants with a low allele frequency in the general population were identified in four disease-associated genes, including two distinct variants in TSPEAR, associated with syndromic and isolated TA in one family each; a variant in LAMB3 associated with syndromic TA in one family; and a variant in BCOR plus a disease-associated WNT10A variant in one family with syndromic TA. With the notable exception of WNT10A (Tooth agenesis, selective, 4, MIM $\#$150400), the genotype-phenotype relationships described in the present cohort represent an expansion of the clinical spectrum associated with these genes: TSPEAR (Deafness, autosomal recessive 98, MIM $\#$614861), LAMB3 (Amelogenesis imperfecta, type IA, MIM $\#$104530; Epidermolysis bullosa, junctional, MIMs $\#$226700 and $\#$226650), and BCOR (Microphthalmia, syndromic 2, MIM $\#$300166). We provide evidence supporting the candidacy of these genes with TA, and propose TSPEAR as a novel nonsyndromic TA gene. Our data also suggest potential multilocus genomic variation, or mutational burden, in a single family, involving the BCOR and WNT10A loci, underscoring the complexity of the genotype-phenotype relationship in the common complex trait of TA.

}, keywords = {Anodontia, Cell Adhesion Molecules, Child, Child, Preschool, Female, Genetic Markers, Humans, Male, Mutation, Pedigree, Phenotype, Proteins, Proto-Oncogene Proteins, Repressor Proteins, Turkey, Wnt Proteins}, issn = {1432-1203}, doi = {10.1007/s00439-018-1907-y}, author = {Du, Renqian and Dinckan, Nuriye and Song, Xiaofei and Coban-Akdemir, Zeynep and Jhangiani, Shalini N and Guven, Yeliz and Aktoren, Oya and Kayserili, H{\"u}lya and Petty, Lauren E and Muzny, Donna M and Below, Jennifer E and Boerwinkle, Eric and Wu, Nan and Gibbs, Richard A and Posey, Jennifer E and Lupski, James R and Letra, Ariadne and Uyguner, Z Oya} } @article {385, title = {Whole-Exome Sequencing Identifies Novel Variants for Tooth Agenesis.}, journal = {J Dent Res}, volume = {97}, year = {2018}, month = {2018 Jan}, pages = {49-59}, abstract = {

Tooth agenesis is a common craniofacial abnormality in humans and represents failure to develop 1 or more permanent teeth. Tooth agenesis is complex, and variations in about a dozen genes have been reported as contributing to the etiology. Here, we combined whole-exome sequencing, array-based genotyping, and linkage analysis to identify putative pathogenic variants in candidate disease genes for tooth agenesis in 10 multiplex Turkish families. Novel homozygous and heterozygous variants in LRP6, DKK1, LAMA3, and COL17A1 genes, as well as known variants in WNT10A, were identified as likely pathogenic in isolated tooth agenesis. Novel variants in KREMEN1 were identified as likely pathogenic in 2 families with suspected syndromic tooth agenesis. Variants in more than 1 gene were identified segregating with tooth agenesis in 2 families, suggesting oligogenic inheritance. Structural modeling of missense variants suggests deleterious effects to the encoded proteins. Functional analysis of an indel variant (c.3607+3_6del) in LRP6 suggested that the predicted resulting mRNA is subject to nonsense-mediated decay. Our results support a major role for WNT pathways genes in the etiology of tooth agenesis while revealing new candidate genes. Moreover, oligogenic cosegregation was suggestive for complex inheritance and potentially complex gene product interactions during development, contributing to improved understanding of the genetic etiology of familial tooth agenesis.

}, keywords = {Anodontia, Female, Genetic Linkage, Genetic Variation, Humans, Intercellular Signaling Peptides and Proteins, Laminin, Low Density Lipoprotein Receptor-Related Protein-6, Male, Membrane Proteins, Mutation, Missense, Pedigree, Real-Time Polymerase Chain Reaction, Turkey, Whole Exome Sequencing, Wnt Proteins}, issn = {1544-0591}, doi = {10.1177/0022034517724149}, author = {Dinckan, N and Du, R and Petty, L E and Coban-Akdemir, Z and Jhangiani, S N and Paine, I and Baugh, E H and Erdem, A P and Kayserili, H and Doddapaneni, H and Hu, J and Muzny, D M and Boerwinkle, E and Gibbs, R A and Lupski, J R and Uyguner, Z O and Below, J E and Letra, A} } @article {12, title = {Novel mutations in LRP6 highlight the role of WNT signaling in tooth agenesis.}, journal = {Genet Med}, volume = {18}, year = {2016}, month = {2016 11}, pages = {1158-1162}, abstract = {

PURPOSE: We aimed to identify a novel genetic cause of tooth agenesis (TA) and/or orofacial clefting (OFC) by combining whole-exome sequencing (WES) and targeted resequencing in a large cohort of TA and OFC patients.

METHODS: WES was performed in two unrelated patients: one with severe TA and OFC and another with severe TA only. After deleterious mutations were identified in a gene encoding low-density lipoprotein receptor-related protein 6 (LRP6), all its exons were resequenced with molecular inversion probes in 67 patients with TA, 1,072 patients with OFC, and 706 controls.

RESULTS: We identified a frameshift (c.4594delG, p.Cys1532fs) and a canonical splice-site mutation (c.3398-2A>C, p.?) in LRP6, respectively, in the patient with TA and OFC and in the patient with severe TA only. The targeted resequencing showed significant enrichment of unique LRP6 variants in TA patients but not in nonsyndromic OFC patients. Of the five variants in patients with TA, two affected the canonical splice site and three were missense variants; all variants segregated with the dominant phenotype, and in one case the missense mutation occurred de novo.

CONCLUSION: Mutations in LRP6 cause TA in humans.Genet Med 18 11, 1158-1162.

}, keywords = {Adolescent, Anodontia, Child, Exome, Female, Frameshift Mutation, Genetic Predisposition to Disease, Humans, Low Density Lipoprotein Receptor-Related Protein-6, Male, Mutation, Missense, Pedigree, Sequence Analysis, DNA, Wnt Signaling Pathway}, issn = {1530-0366}, doi = {10.1038/gim.2016.10}, author = {Ockeloen, Charlotte W and Khandelwal, Kriti D and Dreesen, Karoline and Ludwig, Kerstin U and Sullivan, Robert and van Rooij, Iris A L M and Thonissen, Michelle and Swinnen, Steven and Phan, Milien and Conte, Federica and Ishorst, Nina and Gilissen, Christian and RoaFuentes, Laury and van de Vorst, Maartje and Henkes, Arjen and Steehouwer, Marloes and van Beusekom, Ellen and Bloemen, Marjon and Vankeirsbilck, Bruno and Berg{\'e}, Stefaan and Hens, Greet and Schoenaers, Joseph and Poorten, Vincent Vander and Roosenboom, Jasmien and Verdonck, An and Devriendt, Koen and Roeleveldt, Nel and Jhangiani, Shalini N and Vissers, Lisenka E L M and Lupski, James R and de Ligt, Joep and Von den Hoff, Johannes W and Pfundt, Rolph and Brunner, Han G and Zhou, Huiqing and Dixon, Jill and Mangold, Elisabeth and van Bokhoven, Hans and Dixon, Michael J and Kleefstra, Tjitske and Hoischen, Alexander and Carels, Carine E L} } @article {233, title = {Whole exome sequencing identifies three novel mutations in ANTXR1 in families with GAPO syndrome.}, journal = {Am J Med Genet A}, volume = {164A}, year = {2014}, month = {2014 Sep}, pages = {2328-34}, abstract = {

GAPO syndrome (OMIM$\#$230740) is the acronym for growth retardation, alopecia, pseudoanodontia, and optic atrophy. About 35 cases have been reported, making it among one of the rarest recessive conditions. Distinctive craniofacial features including alopecia, rarefaction of eyebrows and eyelashes, frontal bossing, high forehead, mid-facial hypoplasia, hypertelorism, and thickened eyelids and lips make GAPO syndrome a clinically recognizable phenotype. While this genomic study was in progress mutations in ANTXR1 were reported to cause GAPO syndrome. In our study we performed whole exome sequencing (WES) for five affected individuals from three Turkish kindreds segregating the GAPO trait. Exome sequencing analysis identified three novel homozygous mutations including; one frame-shift (c.1220_1221insT; p.Ala408Cysfs*2), one splice site (c.411A>G; p.Gln137Gln), and one non-synonymous (c.1150G>A; p.Gly384Ser) mutation in the ANTXR1 gene. Our studies expand the allelic spectrum in this rare condition and potentially provide insight into the role of ANTXR1 in the regulation of the extracellular matrix.

}, keywords = {Adolescent, Adult, Alopecia, Anodontia, Base Sequence, Child, Chromosome Segregation, DNA Mutational Analysis, Exome, Facies, Family, Female, Growth Disorders, Humans, Male, Molecular Sequence Data, Mutation, Neoplasm Proteins, Optic Atrophies, Hereditary, Pedigree, Protein Structure, Tertiary, Receptors, Cell Surface}, issn = {1552-4833}, doi = {10.1002/ajmg.a.36678}, author = {Bayram, Yavuz and Pehlivan, Davut and Karaca, Ender and Gambin, Tomasz and Jhangiani, Shalini N and Erdin, Serkan and Gonzaga-Jauregui, Claudia and Wiszniewski, Wojciech and Muzny, Donna and Elcioglu, Nursel H and Yildirim, M Selman and Bozkurt, Banu and Zamani, Ayse Gul and Boerwinkle, Eric and Gibbs, Richard A and Lupski, James R} }