Clinical, genetic, epidemiologic, evolutionary, and functional delineation of TSPEAR-related autosomal recessive ectodermal dysplasia 14

• Published in: HGG advances Vol. 4; no. 2; p. 100186
• Main Authors: Lin, Sheng-Jia, Orr, David, Holden, Simon, Harrison, Mike, Burrows, Nigel, Petree, Cassidy, Donnelly, Deirdre, Ambrose, J.C., Arumugam, P., Boardman-Pretty, F., Chan, G.C., Henderson, S., Kasperaviciute, D., Kayikci, M., Kousathanas, A., Lahnstein, L., Lakey, A., Lopez, F.J., Maleady-Crowe, F., O‘Donovan, P., Patch, C., Pereira, M.B., Rahim, T., Savage, K., Sieghart, A., Taylor Tavares, A.L., Thomas, E.R.A., Tucci, A., Welland, M.J., Williams, E., Zurek, Birte, Demidov, German, Schulze-Hentrich, Julia M., Kessler, Christoph, Traschütz, Andreas, Schöls, Ludger, Scheffer, Hans, Steyaert, Wouter, Sablauskas, Karolis, van Os, Nienke, Janssen, Erik, Yaldiz, Burcu, Kleefstra, Tjitske, Brookes, Anthony J., Mehtarizadeh, Mehdi, Töpf, Ana, Banka, Siddharth, Faivre, Laurence, Bruel, Ange-Line, Peyron, Christine, Pélissier, Aurore, Laurie, Steven, Matalonga, Leslie, Paramonov, Ida, Lochmüller, Hanns, Gumus, Gulcin, Hanauer, Marc, Havrylenko, Svitlana, Izem, Katia, Nelson, Isabelle, Eymard, Bruno, Macek, Milan, Turnovec, Marek, Thomasová, Dana, Kremlik, Vlastimil, Parkinson, Helen, Robinson, Peter, Hanna, Mike, Houlden, Henry, Vandrovcova, Jana, Muntoni, Francesco, Sarkozy, Anna, Van de Vondel, Liedewei, Banfi, Sandro, Aretz, Stefan, Spier, Isabel, José, Celina São, Ferreira, Marta, Carneiro, Fátima, Johansson, Lennart, van der Vries, Gerben, Roelofs-Prins, Dieuwke, Castello, Raffaele, Morleo, Manuela, De la Paz, Manuel Posada, Sánchez, Eva Bermejo, Alonso García de la Rosa, F. Javier, Ciolfi, Andrea, Renieri, Alessandra, Benetti, Elisa, Lohmann, Katja, Macaya, Alfons, Marcé-Grau, Anna, Polavarapu, Kiran, Beeson, David, Udd, Bjarne, Holinski-Feder, Elke, Steinke-Lange, Verena, Schröck, Evelin, Varshney, Gaurav K.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 13.04.2023; Elsevier
• Subjects: Animals; Autosomal recessive ectodermal dysplasia type 14; Closca; Conical teeth; Ectodermal dysplasia; Ectodermal Dysplasia - epidemiology; Enamel knot; Extracellular matrix dependant signalling; Hypodontia; Mice; Phylogeny; Tooth - pathology; TSPEAR; WNT10A; Zebrafish; zebrafish fin regeneration; Closca; WNT10A; zebrafish fin regeneration; Conical teeth; Hypodontia; Enamel knot; TSPEAR; Extracellular matrix dependant signalling; Ectodermal dysplasia; Autosomal recessive ectodermal dysplasia type 14
• ISSN: 2666-2477; 2666-2477
• DOI: 10.1016/j.xhgg.2023.100186

TSPEAR variants cause autosomal recessive ectodermal dysplasia (ARED) 14. The function of TSPEAR is unknown. The clinical features, the mutation spectrum, and the underlying mechanisms of ARED14 are poorly understood. Combining data from new and previously published individuals established that ARED14 is primarily characterized by dental anomalies such as conical tooth cusps and hypodontia, like those seen in individuals with WNT10A-related odontoonychodermal dysplasia. AlphaFold-predicted structure-based analysis showed that most of the pathogenic TSPEAR missense variants likely destabilize the β-propeller of the protein. Analysis of 100000 Genomes Project (100KGP) data revealed multiple founder TSPEAR variants across different populations. Mutational and recombination clock analyses demonstrated that non-Finnish European founder variants likely originated around the end of the last ice age, a period of major climatic transition. Analysis of gnomAD data showed that the non-Finnish European population TSPEAR gene-carrier rate is ∼1/140, making it one of the commonest AREDs. Phylogenetic and AlphaFold structural analyses showed that TSPEAR is an ortholog of drosophila Closca, an extracellular matrix-dependent signaling regulator. We, therefore, hypothesized that TSPEAR could have a role in enamel knot, a structure that coordinates patterning of developing tooth cusps. Analysis of mouse single-cell RNA sequencing (scRNA-seq) data revealed highly restricted expression of Tspear in clusters representing enamel knots. A tspeara−/−;tspearb−/− double-knockout zebrafish model recapitulated the clinical features of ARED14 and fin regeneration abnormalities of wnt10a knockout fish, thus suggesting interaction between tspear and wnt10a. In summary, we provide insights into the role of TSPEAR in ectodermal development and the evolutionary history, epidemiology, mechanisms, and consequences of its loss of function variants. We show that TSPEAR variants cause a frequent recessive ectodermal dysplasia characterized by dental anomalies and multiple founder variants that originated around the end of the last ice age; pathogenic variants destabilize the TSPEAR β-propeller; and TSPEAR is a likely wnt10a-interacting extracellular matrix-dependent signaling regulator with highly restricted expression.