Deficiency in complex II of the respiratory chain, presenting as a leukodystrophy in two sisters with Leigh syndrome.

We report 2 sisters with a degenerative neurological disorder presenting clinically as a leukodystrophy. CT scan and MRI demonstrated small symmetrical foci of necrosis in the substentia nigra and in the basal ganglia typical of Leigh syndrome and diffuse cerebral white matter abnormalities. In these patients a deficiency in complex II of the respiratory chain was demonstrated in isolated mitochondria from muscle, as well as in fibroblasts and lymphocytes.