Conflict of interest: Drs. Sheldon and Boles are employees of Courtagen Diagnostic Laboratory.
Severe infantile leigh syndrome associated with a rare mitochondrial ND6 mutation, m.14487T>C
Article first published online: 27 JUN 2013
Copyright © 2013 Wiley Periodicals, Inc.
American Journal of Medical Genetics Part A
Volume 161, Issue 8, pages 2020–2023, August 2013
How to Cite
2013. Severe infantile Leigh syndrome associated with a rare mitochondrial ND6 mutation, m.14487T>C. Am J Med Genet Part A. 161A:2020–2023., , , , .
- Issue published online: 24 JUL 2013
- Article first published online: 27 JUN 2013
- Manuscript Accepted: 23 FEB 2013
- Manuscript Received: 9 JAN 2013
- Warren Lammert and Family
- Dan Wright and family
- Leigh disease;
- deep sequencing;
- mitochondrial disease
We describe a case of severe infantile-onset complex I deficiency in association with an apparent de novo near-homoplasmic mutation (m.14487T>C) in the mitochondrial ND6 gene, which was previously associated with Leigh syndrome and other neurological disorders. The mutation was near-homoplasmic in muscle by NextGen sequencing (99.4% mutant), homoplasmic in muscle by Sanger sequencing, and it was associated with a severe complex I deficiency in both muscle and fibroblasts. This supports previous data regarding Leigh syndrome being on the severe end of a phenotypic spectrum including progressive myoclonic epilepsy, childhood-onset dystonia, bilateral striatal necrosis, and optic atrophy, depending on the proportion of mutant heteroplasmy. While the mother in all previously reported cases was heteroplasmic, the mother and brother of this case were homoplasmic for the wild-type, m.14487T. Importantly, the current data demonstrate the potential for cases of mutations that were previously reported to be homoplasmic by Sanger sequencing to be less homoplasmic by NextGen sequencing. This case underscores the importance of considering mitochondrial DNA mutations in families with a negative family history, even in offspring of those who have tested negative for a specific mtDNA mutation. © 2013 Wiley Periodicals, Inc.