Mitochondrial myopathy in a child with a muscle-restricted mutation in the mitochondrial transfer RNAAsn gene.

Abstract

We report an 11-year-old boy with exercise-related myopathy, and a novel mutation m.5669G>A in the mitochondrial tRNA Asparagine gene (mt-tRNA(Asn), MTTN). Muscle biopsy studies showed COX-negative, SDH-positive fibers at histochemistry and biochemical defects of oxidative metabolism. The m.5669G>A mutation was present only in patient's muscle resulting in the first muscle-specific MTTN mutation. Mt-tRNA(Asn) steady-state levels and in silico predictions supported the pathogenicity of this mutation. A mitochondrial myopathy should be considered in the differential diagnosis of exercise intolerance in children.

• Authors: Claudio Bruno, Denise Cassandrini, Fabiana Fattori, Marina Pedemonte, Chiara Fiorillo, Giorgia Brigati, Giacomo Brisca, Carlo Minetti, Filippo M Santorelli
• Journal: Biochemical and biophysical research communications (Biochem Biophys Res Commun) Vol. 412 Issue 4 Pg. 518-21 (Sep 09 2011) ISSN: 1090-2104 [Electronic] United States
• PMID: 21741368 (Publication Type: Case Reports, Journal Article)
• Copyright: Copyright © 2011 Elsevier Inc. All rights reserved.

Chemical References

• DNA, Mitochondrial
• RNA, Mitochondrial
• RNA, Transfer, Asn
• RNA

Topics

• Base Sequence
• Child
• DNA, Mitochondrial (genetics)
• Exercise Tolerance (genetics)
• Humans
• Male
• Mitochondria, Muscle (genetics)
• Mitochondrial Myopathies (genetics, pathology, physiopathology)
• Molecular Sequence Data
• Muscle Weakness (genetics, pathology)
• Muscle, Skeletal (metabolism, pathology)
• Nucleic Acid Conformation
• RNA (chemistry, genetics)
• RNA, Mitochondrial
• RNA, Transfer, Asn (chemistry, genetics)