Journal Article

Genotype–phenotype correlations in recessive titinopathies

Astrea, Guja, Sarkozy, Anna, Qureshi, Talha, Barresi, Rita, Ehrstedt, Christoffer, Julien, Cedric, Rojas-García, Ricardo, Luque, Helena, Malandrini, Alessandro, Savarese, Marco, Muntoni, Francesco, Torella, Annalaura, Oates, Emily C., Jokela, Manu, Tasca, Giorgio, Petiot, Philippe, Hackman, Peter, de Munain, Adolfo López, Muelas, Nuria, Pane, Marika, Casar-Borota, Olivera, Johari, Mridul, Zhao, Chong-Bo, Santorelli, Filippo Maria, Udd, Bjarne, Illa, Isabel, Vílchez, Juan J., Nigro, Vincenzo, Bruno, Claudio, Davis, Mark, Fodstad, Heidi, Vihola, Anna, Lonardo, Fortunato, Mercuri, Eugenio, Díaz-Manera, Jordi, Fiorillo, Chiara, Kuntzer, Thierry, Luo, Sushan, Ferreiro, Ana, Sáenz, Amets, Välipakka, Salla

2020

Overview

Purpose High throughput sequencing analysis has facilitated the rapid analysis of the entire titin ( TTN ) coding sequence. This has resulted in the identification of a growing number of recessive titinopathy patients. The aim of this study was to (1) characterize the causative genetic variants and clinical features of the largest cohort of recessive titinopathy patients reported to date and (2) to evaluate genotype–phenotype correlations in this cohort. Methods We analyzed clinical and genetic data in a cohort of patients with biallelic pathogenic or likely pathogenic TTN variants. The cohort included both previously reported cases (100 patients from 81 unrelated families) and unreported cases (23 patients from 20 unrelated families). Results Overall, 132 causative variants were identified in cohort members. More than half of the cases had hypotonia at birth or muscle weakness and a delayed motor development within the first 12 months of life (congenital myopathy) with causative variants located along the entire gene. The remaining patients had a distal or proximal phenotype and a childhood or later (noncongenital) onset. All noncongenital cases had at least one pathogenic variant in one of the final three TTN exons (362–364). Conclusion Our findings suggest a novel association between the location of nonsense variants and the clinical severity of the disease.

• Publisher: Nature Publishing Group US,Elsevier Limited,Nature Publishing Group
• Subject: arthrogryposis / Biomedical and Life Sciences / Biomedicine / cardiomyopathy / Child / congenital myopathy / Connectin - genetics / Genetic Association Studies / Genotype & phenotype / High-Throughput Nucleotide Sequencing / Human Genetics / Humans / Laboratory Medicine / Life Sciences / Muscle Hypotonia / Mutation / Pathology / Patologi / Phenotype / skeletal muscle disorders / titin / Whole genome sequencing