Mitochondrial DNA deletion in oculoskeletal myopathy.

The case of a patient showing bilateral ophthalmoplegia with proximal limb weakness, severe dysphagia and short stature, without family history, is described. The diagnosis of Kearns-Sayre syndrome was excluded because of the absence of pigmentary retinopathy and of all other common manifestations except short stature. The analysis of mitochondrial DNA of the patient's muscle revealed a deleted form accounting for 65% of the total mitochondrial DNA. The deletion, undetectable in the mitochondrial DNA of peripheral blood leukocytes, was apparently indistinguishable from that already described by others in a far more severe form of classic Kearns-Sayre syndrome.