Cybrid studies establish the causal link between the mtDNA m.3890G>A/MT-ND1 mutation and optic atrophy with bilateral brainstem lesions.

Abstract

Complex I (CI) deficiency is a frequent cause of mitochondrial disorders and, in most cases, is due to mutations in CI subunit genes encoded by mitochondrial DNA (mtDNA). In this study, we establish the pathogenic role of the heteroplasmic mtDNA m.3890G>A/MT-ND1 (p.R195Q) mutation, which affects an extremely conserved amino acid position in ND1 subunit of CI. This mutation was found in a young-adult male with optic atrophy resembling Leber's hereditary optic neuropathy (LHON) and bilateral brainstem lesions. The only previously reported case with this mutation was a girl with fatal infantile Leigh syndrome with bilateral brainstem lesions. Transfer of the mutant mtDNA in the cybrid cell system resulted in a marked reduction of CI activity and CI-dependent ATP synthesis in the presence of a normally assembled enzyme. These findings establish the pathogenicity of the m.3890G>A/MT-ND1 mutation and remark the link between CI mutations affecting the mtDNA-encoded ND subunits and LHON-like optic atrophy, which may be complicated by bilateral and symmetric lesions affecting the central nervous system. Peculiar to this mutation is the distribution of the brainstem lesions, with sparing of the striatum in both patients.

• Authors: Leonardo Caporali, Anna Maria Ghelli, Luisa Iommarini, Alessandra Maresca, Maria Lucia Valentino, Chiara La Morgia, Rocco Liguori, Claudia Zanna, Piero Barboni, Vera De Nardo, Andrea Martinuzzi, Giovanni Rizzo, Caterina Tonon, Raffaele Lodi, Maria Antonietta Calvaruso, Martina Cappelletti, Anna Maria Porcelli, Alessandro Achilli, Maria Pala, Antonio Torroni, Valerio Carelli
• Journal: Biochimica et biophysica acta (Biochim Biophys Acta) Vol. 1832 Issue 3 Pg. 445-52 (Mar 2013) ISSN: 0006-3002 [Print] Netherlands
• PMID: 23246842 (Publication Type: Case Reports, Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2012 Elsevier B.V. All rights reserved.

Chemical References

• DNA, Mitochondrial
• Lactates
• NADH Dehydrogenase
• NADH dehydrogenase subunit 1, human

Topics

• Adult
• Amino Acid Sequence
• Brain Stem (metabolism, pathology)
• Cell Line, Tumor
• DNA, Mitochondrial (genetics)
• Female
• Humans
• Hybrid Cells
• Lactates (blood)
• Magnetic Resonance Imaging
• Magnetic Resonance Spectroscopy
• Male
• Molecular Sequence Data
• Muscle, Skeletal (metabolism)
• Mutation, Missense
• NADH Dehydrogenase (genetics, metabolism)
• Optic Atrophies, Hereditary (blood, genetics, metabolism)
• Pedigree
• Sequence Homology, Amino Acid