Mitochondrial DNA copy number in affected and unaffected LHON mutation carriers

• Published in: BMC research notes Vol. 11; no. 1; pp. 911 - 4
• Main Authors: Bianco, Angelica, Valletti, Alessio, Longo, Giovanna, Bisceglia, Luigi, Montoya, Julio, Emperador, Sonia, Guerriero, Silvana, Petruzzella, Vittoria
• Format: Journal Article
• Language: English
• Published: London BioMed Central 20.12.2018; BioMed Central Ltd; BMC
• Subjects: Biomedical and Life Sciences; Biomedicine; Biosynthesis; Copy number; Data Note; Datasets; Deoxyribonucleic acid; DNA; DNA Copy Number Variations - genetics; DNA, Mitochondrial - genetics; Female; Genomes; Heteroplasmy; Heterozygote; Humans; Incomplete penetrance; Italy; Leber’s hereditary optic neuropathy; Life Sciences; Male; Medicine/Public Health; Mitochondrial DNA; Mitochondrial genome; mtDNA copy number; Mutation; Optic Atrophy, Hereditary, Leber - genetics; Optic Atrophy, Hereditary, Leber - pathology; Optic Atrophy, Hereditary, Leber - physiopathology; Optic neuropathy; Pedigree; Penetrance; Spain; Italy; Spain; Leber’s hereditary optic neuropathy; mtDNA copy number; Mitochondrial genome; Incomplete penetrance
• ISSN: 1756-0500; 1756-0500
• DOI: 10.1186/s13104-018-4025-y

Objectives Leber’s hereditary optic neuropathy (LHON) is a mitochondrial genetic disease characterized by a variable and reduced penetrance. Individuals carrying a primary LHON-causing mitochondrial DNA (mtDNA) mutation may either remain asymptomatic lifelong, as unaffected carriers, or develop sudden central visual loss that rapidly aggravates over some weeks. Over the years several genetic/environmental triggers able to modulate the risk of developing LHON have been proposed. We provided data supporting a possible correlation between LHON penetrance and the mtDNA copy number, a raw index of mitochondrial mass, whose increase could represent a compensatory response that cells implement to alleviate the pathogenic effect of the primary LHON-causing mtDNA mutations. Data description We collected Italian and Spanish subjects harboring one of the three common LHON primary mutations, either in heteroplasmic or homoplasmic status. For each population we were able to discriminate between affected subjects presenting typical clinical tracts of LHON and LHON-causing mutation carriers showing no symptoms correlated with vision loss. Each subject has been characterized for the presence of a LHON primary mutation, for its status of homoplasmy or heteroplasmy, and for the mtDNA content per cell, expressed as relative mtDNA/nDNA ratio respect to controls. Additional clinical information is present for all the Italian subjects.