A1 Refereed original research article in a scientific journal
The crucial role of titin in fetal development: recurrent miscarriages and bone, heart and muscle anomalies characterise the severe end of titinopathies spectrum
Authors: Di Feo Maria Francesca, Lillback Victoria, Jokela Manu, McEntagart Meriel, Homfray Tessa, Giorgio Elisa, Cavalchini Guido C Casalis, Brusco Alfredo, Iascone Maria, Spaccini Luigina, D'Oria Patrizia, Savarese Marco, Udd Bjarne
Publisher: BMJ PUBLISHING GROUP
Publication year: 2023
Journal: Journal of Medical Genetics
Journal name in source: JOURNAL OF MEDICAL GENETICS
Journal acronym: J MED GENET
Volume: 60
Issue: 9
First page : 866
Last page: 873
Number of pages: 8
ISSN: 0022-2593
eISSN: 1468-6244
DOI: https://doi.org/10.1136/jmg-2022-109018
Web address : https://jmg.bmj.com/content/early/2023/03/28/jmg-2022-109018
Background Titin truncating variants (TTNtvs) have been associated with several forms of myopathies and/or cardiomyopathies. In homozygosity or in compound heterozygosity, they cause a wide spectrum of recessive phenotypes with a congenital or childhood onset. Most recessive phenotypes showing a congenital or childhood onset have been described in subjects carrying biallelic TTNtv in specific exons. Often karyotype or chromosomal microarray analyses are the only tests performed when prenatal anomalies are identified. Thereby, many cases caused by TTN defects might be missed in the diagnostic evaluations. In this study, we aimed to dissect the most severe end of the titinopathies spectrum. Methods We performed a retrospective study analysing an international cohort of 93 published and 10 unpublished cases carrying biallelic TTNtv. Results We identified recurrent clinical features showing a significant correlation with the genotype, including fetal akinesia (up to 62%), arthrogryposis (up to 85%), facial dysmorphisms (up to 73%), joint (up to 17%), bone (up to 22%) and heart anomalies (up to 27%) resembling complex, syndromic phenotypes. Conclusion We suggest TTN to be carefully evaluated in any diagnostic process involving patients with these prenatal signs. This step will be essential to improve diagnostic performance, expand our knowledge and optimise prenatal genetic counselling.