Figure 3

Classification tree of four mtDNAs with m.10680G > A. Two reported LHON mtDNAs (Le1107 [15] and FJ986465 [16]) were adopted from published sources. The revised Cambridge reference sequence (rCRS) [27] was included to show the phylogenetic relationship of the lineages and haplogroup-specific variants. The order of variants on each uninterrupted branch section is arbitrary. Haplogroup names were placed on each branch to show their hierarchical and nested positions within macrohaplogroups M and N. Recurrent variants were underlined. Deletion of nucleotide(s) was indicated by suffix "d". Length mutations of the C-tract in region 303-309 were omitted from the tree. Mutation m.10680G > A was marked in boldfaced. The synonymous and non-synonymous coding-region variants in these mtDNAs were further denoted by "/s" and "/ns", respectively. Variations in the ribosomal RNA genes and tRNA genes were denoted by "/r" and "/t", respectively.