Making sense of missense variants in TTN-related congenital myopathies
Martin Rees
(1)
,
Roksana Nikoopour
(1)
,
Atsushi Fukuzawa
(1)
,
Ay Lin Kho
(1)
,
Miguel Fernandez-Garcia
(2)
,
Elizabeth Wraige
(2)
,
Istvan Bodi
(1)
,
Charu Deshpande
(3)
,
Özkan Özdemir
(4)
,
Hülya-Sevcan Daimagüler
(4)
,
Mark Pfuhl
(1)
,
Mark Holt
(1)
,
Birgit Brandmeier
(1)
,
Sarah Grover
(1)
,
Joël Fluss
(5)
,
Cheryl Longman
(6)
,
Maria Elena Farrugia
(6)
,
Emma Matthews
(7)
,
Michael Hanna
(7)
,
Francesco Muntoni
(8, 9)
,
Anna Sarkozy
(8)
,
Rahul Phadke
(8)
,
Ros Quinlivan
(8)
,
Emily Oates
(8, 10, 11)
,
Rolf Schröder
(12)
,
Christian Thiel
(13)
,
Jens Reimann
(14)
,
Nicol Voermans
(15)
,
Corrie Erasmus
(15)
,
Erik-Jan Kamsteeg
(15)
,
Chaminda Konersman
(16)
,
Carla Grosmann
,
Shane Mckee
(17)
,
Sandya Tirupathi
(18)
,
Steven Moore
(19)
,
Ekkehard Wilichowski
(20)
,
Elke Hobbiebrunken
(20)
,
Gabriele Dekomien
,
Isabelle Richard
(21, 22)
,
Peter van den Bergh
(23)
,
Cristina Domínguez-González
(24)
,
Sebahattin Cirak
(4)
,
Ana Ferreiro
(25)
,
Heinz Jungbluth
(1, 2)
,
Mathias Gautel
(1)
1
King‘s College London
2 Evelina London Children's Hospital
3 Guy's Hospital [London]
4 University of Cologne
5 Children’s University Hospital of Geneva [Switzerland]
6 Queen Elizabeth University Hospital (Glasgow)
7 National Hospital for Neurology and Neurosurgery [London, UK]
8 GOSH - Great Ormond Street Hospital for Children [London]
9 UCL - University College of London [London]
10 UNSW - University of New South Wales [Sydney]
11 Westmead Hospital [Sydney]
12 University Hospital Erlangen = Uniklinikum Erlangen
13 Universitätsklinikum Erlangen [Erlangen]
14 University of Bonn Medical Centre [Bonn]
15 Radboud University [Nijmegen]
16 Rady Children's Hospital
17 Belfast City Hospital
18 Royal Belfast Hospital for Sick Children
19 University of Iowa [Iowa City]
20 Georg-August-University = Georg-August-Universität Göttingen
21 INTEGRARE - Approches génétiques intégrées et nouvelles thérapies pour les maladies rares
22 Généthon
23 Saint-Luc University Hospital [Brussels, Belgium]
24 Hospital Universitario 12 de Octubre [Madrid]
25 BFA (UMR_8251 / U1133) - Unité de Biologie Fonctionnelle et Adaptative
2 Evelina London Children's Hospital
3 Guy's Hospital [London]
4 University of Cologne
5 Children’s University Hospital of Geneva [Switzerland]
6 Queen Elizabeth University Hospital (Glasgow)
7 National Hospital for Neurology and Neurosurgery [London, UK]
8 GOSH - Great Ormond Street Hospital for Children [London]
9 UCL - University College of London [London]
10 UNSW - University of New South Wales [Sydney]
11 Westmead Hospital [Sydney]
12 University Hospital Erlangen = Uniklinikum Erlangen
13 Universitätsklinikum Erlangen [Erlangen]
14 University of Bonn Medical Centre [Bonn]
15 Radboud University [Nijmegen]
16 Rady Children's Hospital
17 Belfast City Hospital
18 Royal Belfast Hospital for Sick Children
19 University of Iowa [Iowa City]
20 Georg-August-University = Georg-August-Universität Göttingen
21 INTEGRARE - Approches génétiques intégrées et nouvelles thérapies pour les maladies rares
22 Généthon
23 Saint-Luc University Hospital [Brussels, Belgium]
24 Hospital Universitario 12 de Octubre [Madrid]
25 BFA (UMR_8251 / U1133) - Unité de Biologie Fonctionnelle et Adaptative
Emma Matthews
- Function : Author
- PersonId : 806119
- ORCID : 0000-0002-3810-306X
Francesco Muntoni
- Function : Author
- PersonId : 759030
- ORCID : 0000-0002-9102-5232
- IdRef : 077207912
Carla Grosmann
- Function : Author
Gabriele Dekomien
- Function : Author
Isabelle Richard
- Function : Author
- PersonId : 176430
- IdHAL : isabelle-richard
- ORCID : 0000-0002-6505-446X
- IdRef : 177586249
Sebahattin Cirak
- Function : Author
- PersonId : 792641
- ORCID : 0000-0003-3040-6477
Abstract
Mutations in the sarcomeric protein titin, encoded by TTN, are emerging as a common cause of myopathies. The diagnosis of a TTN-related myopathy is, however, often not straightforward due to clinico-pathological overlap with other myopathies and the prevalence of TTN variants in control populations. Here, we present a combined clinico-pathological, genetic and biophysical approach to the diagnosis of TTN-related myopathies and the pathogenicity ascertainment of TTN missense variants. We identified 30 patients with a primary TTN-related congenital myopathy (CM) and two truncating variants, or one truncating and one missense TTN variant, or homozygous for one TTN missense variant. We found that TTN-related myopathies show considerable overlap with other myopathies but are strongly suggested by a combination of certain clinico-pathological features. Presentation was typically at birth with the clinical course characterized by variable progression of weakness, contractures, scoliosis and respiratory symptoms but sparing of extraocular muscles. Cardiac involvement depended on the variant position. Our biophysical analyses demonstrated that missense mutations associated with CMs are strongly destabilizing and exert their effect when expressed on a truncating background or in homozygosity. We hypothesise that destabilizing TTN missense mutations phenocopy truncating variants and are a key pathogenic feature of recessive titinopathies that might be amenable to therapeutic intervention.
Origin : Publication funded by an institution