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  • Author: Antônio Carlos Santos x
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Jose Italo Soares Mota, Rui Milton Patrício Silva-Júnior, Clarissa Silva Martins, Ana Carolina Bueno, Luiz Eduardo Wildemberg, Ximene Lima da Silva Antunes, Jorge Guilherme Okanobo Ozaki, Fernanda Borchers Coeli-Lacchini, Carlos Garcia-Peral, Antonio Edson Rocha Oliveira, Antônio Carlos Santos, Ayrton Custodio Moreira, Helio Rubens Machado, Marcelo Volpon dos Santos, Leandro M Colli, Monica R Gadelha, Sonir Roberto R Antonini, and Margaret de Castro

Objectives

To evaluate how telomere length behaves in adamantinomtous craniopharyngioma (aCP) and if it contributes to the pathogenesis of aCPs with and without CTNNB1 mutations.

Design

Retrospective cross-sectional study enrolling 42 aCP patients from 2 tertiary institutions.

Methods

Clinicopathological features were retrieved from the patient’s charts. Fresh frozen tumors were used for RNA and DNA analyses. Telomere length was evaluated by qPCR (T/S ratio). Somatic mutations in TERT promoter (TERTp) and CTNNB1 were detected by Sanger and/or whole-exome sequencing. We performed RNA-Seq to identify differentially expressed genes in aCPs presenting with shorter or longer telomere lengths.

Results

Mutations in CTNNB1 were detected in 29 (69%) tumors. There was higher frequency of CTNNB1 mutations in aCPs from patients diagnosed under the age of 15 years (85% vs 15%; P = 0.04) and a trend to recurrent disease (76% vs 24%; P = 0.1). No mutation was detected in the TERTp region. The telomeres were shorter in CTNNB1-mutated aCPs (0.441, IQR: 0.297–0.597vs 0.607, IQR: 0.445–0.778; P = 0.04), but it was neither associated with clinicopathological features nor with recurrence. RNAseq identified a total of 387 differentially expressed genes, generating two clusters, being one enriched for short telomeres and CTNNB1-mutated aCPs.

Conclusions: CTNNB1

mutations are more frequent in children and adolescents and appear to associate with progressive disease. CTNNB1-mutated aCPs have shorter telomeres, demonstrating a relationship between the Wnt/β-catenin pathway and telomere biology in the pathogenesis of aCPs.

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Lucía Sentchordi-Montané, Sara Benito-Sanz, Miriam Aza-Carmona, Francisca Díaz-González, Silvia Modamio-Høybjør, Carolina de la Torre, Julián Nevado, Pablo Ruiz-Ocaña, Carolina Bezanilla-López, Pablo Prieto, Pilar Bahíllo-Curieses, Atilano Carcavilla, Inés Mulero-Collantes, Ana C Barreda-Bonis, Jaime Cruz-Rojo, Joaquín Ramírez-Fernández, José Antonio Bermúdez de la Vega, André M Travessa, Jesús González de Buitrago Amigo, Angela del Pozo, Elena Vallespín, Mario Solís, Carlos Goetz, Ángel Campos-Barros, Fernando Santos-Simarro, Isabel González-Casado, Purificación Ros-Pérez, Manuel Parrón-Pajares, and Karen E Heath

Objective

Next generation sequencing (NGS) has expanded the diagnostic paradigm turning the focus to the growth plate. The aim of the study was to determine the prevalence of variants in genes implicated in skeletal dysplasias in probands with short stature and mild skeletal anomalies.

Design

Clinical and radiological data were collected from 108 probands with short stature and mild skeletal anomalies.

Methods

A customized skeletal dysplasia NGS panel was performed. Variants were classified using ACMG recommendations and Sherloc. Anthropometric measurements and skeletal anomalies were subsequently compared in those with or without an identified genetic defect.

Results

Heterozygous variants were identified in 21/108 probands (19.4%). Variants were most frequently identified in ACAN (n = 10) and IHH (n = 7) whilst one variant was detected in COL2A1, CREBBP, EXT1, and PTPN11. Statistically significant differences (P < 0.05) were observed for sitting height/height (SH/H) ratio, SH/H ratio standard deviation score (SDS), and the SH/H ratio SDS >1 in those with an identified variant compared to those without.

Conclusions

A molecular defect was elucidated in a fifth of patients. Thus, the prevalence of mild forms of skeletal dysplasias is relatively high in individuals with short stature and mild skeletal anomalies, with variants in ACAN and IHH accounting for 81% of the cases. An elevated SH/H ratio appears to be associated with a greater probability in detecting a variant, but no other clinical or radiological feature has been found determinant to finding a genetic cause. Currently, we cannot perform extensive molecular studies in all short stature individuals so detailed clinical and radiological phenotyping may orientate which are the candidate patients to obtain worthwhile results. In addition, detailed phenotyping of probands and family members will often aid variant classification.