Back to Search
Start Over
A new titinopathy: Childhood-juvenile onset Emery-Dreifuss-like phenotype without cardiomyopathy.
- Source :
-
Neurology [Neurology] 2015 Dec 15; Vol. 85 (24), pp. 2126-35. Date of Electronic Publication: 2015 Nov 18. - Publication Year :
- 2015
-
Abstract
- Objective: To identify the genetic defects present in 3 families with muscular dystrophy, contractures, and calpain 3 deficiency.<br />Methods: We performed targeted exome sequencing on one patient presenting a deficiency in calpain 3 on Western blot but for which mutations in the gene had been excluded. The identification of a homozygous truncating mutation in the M-line part of titin prompted us to sequence this region in 2 additional patients presenting similar clinical and biochemical characteristics.<br />Results: The 3 patients shared similar features: coexistence of limb-girdle weakness and early-onset diffuse joint contractures without cardiomyopathy. The biopsies showed rimmed vacuoles, a dystrophic pattern, and secondary reduction in calpain 3. We identified a novel homozygous mutation in the exon Mex3 of the TTN gene in the first patient. At protein level, this mutation introduces a stop codon at the level of Mex3. Interestingly, we identified truncating mutations in both alleles in the same region of the TTN gene in patients from 2 additional families. Molecular protein analyses confirm loss of the C-ter part of titin.<br />Conclusions: Our study broadens the phenotype of titinopathies with the report of a new clinical entity with prominent contractures and no cardiac abnormality and where the recessive mutations lead to truncation of the M-line titin and secondary calpain 3 deficiency.<br /> (© 2015 American Academy of Neurology.)
Details
- Language :
- English
- ISSN :
- 1526-632X
- Volume :
- 85
- Issue :
- 24
- Database :
- MEDLINE
- Journal :
- Neurology
- Publication Type :
- Academic Journal
- Accession number :
- 26581302
- Full Text :
- https://doi.org/10.1212/WNL.0000000000002200