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Pham C, Munoz-Martin N, Podliesna S, Milano A, Beekman L, Vermeer A, Frantzen C, Jansen S, Van De Laar I, Nieuwhof K, Christiaans I, Bezzina C, Lodder E. Altered auto-phosphorylation of novel TNNI3K variants associated with AV-nodal re-entry tachycardia and conduction disease. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.0339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
In the past decade, we and others have reported three families with rare genetic variants in TNNI3K, encoding the cardiac-specific troponin-I interacting kinase (TNNI3K), co-segregating with a mixed, but highly penetrant, cardiac phenotype that features predominant atrial/junctional tachycardia occurring in combination with cardiac conduction disease and dilated cardiomyopathy. We demonstrated that while the p.Thr539Ala and p.Gly526Asp TNNI3K variants had decreased auto-phosphorylation activity the p.Glu768Lys variant, present in 3 independent families, leads to increased auto-phosphorylation levels, in line with the finding that increased levels of Tnni3k expression are associated with slower atrial-ventricular conduction in mice.
Objective
Identifying new genetic variants in the TNNI3K gene associated with cardiac disease and assessing their impact on TNNI3K auto-phosphorylation levels.
Methods
Through next generation sequencing of a panel of genes associated with cardiac disease we assessed TNNI3K in patients with cardiac arrhythmias and cardiomyopathies. All variants identified were assessed in vitro for effects on auto-phosphorylation. Briefly, wild-type and mutant TNNI3K constructs were transfected into HEK293 cells, protein was extracted after 48 hours and analyzed with anti-flag and anti-phospho-tyrosine antibodies on Western blot.
Results
We identified 7 novel and rare variants in TNNI3K in 11 additional probands, with predominantly cardiac conduction disease, with or without dilated cardiomyopathy, and atrial-ventricular-re-entry-tachycardia (AVNRT). Of these, multiple variants were found to have aberrant auto-phosphorylation including almost absent auto-phosphorylation capacity for one (TNNI3K-p.Val510Leu). All three-independent wild type TNNI3K transfected HEK293 cell lysates showed similar phosphorylated TNNI3K levels and the kinase-dead negative control demonstrated no phosphorylation activity.
Conclusion
We here present 7 novel genetic variants in TNNI3K in patients with a remarkable overlap in cardiac phenotype consisting mainly of AVNRT and cardiac conduction disease. We further show that some of these variants alter the auto-phosphorylation of TNNI3K. These results indicate a more prevalent role of variants in TNNI3K in human cardiac disease and a possible in vitro functional assay to assess the pathogenicity of such variants.
Funding Acknowledgement
Type of funding source: Public grant(s) – National budget only. Main funding source(s): The Dutch Research Council (NWO Talent Scheme VIDI-91718361)
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Affiliation(s)
- C Pham
- Amsterdam UMC - Location Academic Medical Center, Amsterdam, Netherlands (The)
| | - N Munoz-Martin
- Amsterdam UMC - Location Academic Medical Center, Amsterdam, Netherlands (The)
| | - S Podliesna
- Amsterdam UMC - Location Academic Medical Center, Amsterdam, Netherlands (The)
| | - A Milano
- Amsterdam UMC - Location Academic Medical Center, Amsterdam, Netherlands (The)
| | - L Beekman
- Amsterdam UMC - Location Academic Medical Center, Amsterdam, Netherlands (The)
| | - A Vermeer
- Amsterdam UMC - Location Academic Medical Center, Amsterdam, Netherlands (The)
| | - C Frantzen
- University Medical Center Groningen, Groningen, Netherlands (The)
| | - S Jansen
- Amsterdam UMC - Location VUmc, Amsterdam, Netherlands (The)
| | - I Van De Laar
- Erasmus University Medical Centre, Rotterdam, Netherlands (The)
| | - K Nieuwhof
- University Medical Center Groningen, Groningen, Netherlands (The)
| | - I Christiaans
- Amsterdam UMC - Location Academic Medical Center, Amsterdam, Netherlands (The)
| | - C.R Bezzina
- Amsterdam UMC - Location Academic Medical Center, Amsterdam, Netherlands (The)
| | - E.M Lodder
- Amsterdam UMC - Location Academic Medical Center, Amsterdam, Netherlands (The)
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Duker PC, Dortmans A, Lodder E. Establishing the manding function of communicative gestures with individuals with severe/profound mental retardation. Res Dev Disabil 1993; 14:39-49. [PMID: 8469797 DOI: 10.1016/0891-4222(93)90004-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Procedures for teaching communicative gestures to individuals with mental retardation are focused mostly on establishing requesting or manding. It is often taken for granted that when a student has been taught to make a request, that he or she is indeed manding. Five students with severe/profound mental retardation accepted referents, regardless of whether the referents matched the gestures they made. Apparently, their responding could not be defined as manding. A correction procedure, including interruption, physical guidance, verbal instruction, and repetition, was then applied and increased the individuals' correct rejecting of unmatching referents. Data were collected within a multiple baseline design across individuals. It is suggested that assessing student's response when the trainer or teacher delivers items that do not match the referent of a prior request is a necessary part of each training program.
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Affiliation(s)
- P C Duker
- PROCESS Research Group, University of Nijmegen, The Netherlands
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