Do you know of a patient or family with a similar presentation to that described below?

• Clinical presentation: Two affected brothers presented in their mid 50s with weakness about the ankles, poor balance and a chronic cough. There were cerebellar signs with saccadic interruption of eye movements and a wide-based gait, and later on dysarthria.
• The mode of inheritance is probably recessive (parents consanguineous), but could be dominant (germline de novo).
• Creatine kinase levels were elevated (as high as 580 and 1020).
• Nerve conduction studies indicated a severe sensorimotor peripheral neuropathy, at least as prominent as the cerebellar ataxia.
• Muscle biopsies exhibit numerous atrophic fibres and group atrophy, in keeping with a neurogenic cause.
• Electron microscopy displayed subsarcolemmal accumulation of pleomorphic mitochondria with large electron dense inclusions.
• MRI of the head showed progressive atrophy of the cerebellum, principally of the vermis, and thinning of the brainstem.