Ocular myopathy and mitochondrial DNA deletion. A presentation of seven identified Danish patients

This paper summarizes the data on Danish patients with ocular myopathy and mitochondrial DNA deletion (delta mtDNA). To date, a single Danish patient harbouring delta mtDNA has been reported. In the present study we have identified seven additional ones and characterized the nature of their deletion, both qualitatively and quantitatively. All patients are sporadic cases each with a single deletion in the range of 2.3-78 kb, the delta mtDNA accounting for 10-75% of the total mtDNA in the biopsy analyzed. The clinical severity correlates with the percentage of deletion molecules, and not with the size of the deletion.