Expanding the phenotype of the 8344 transfer RNAlysine mitochondrial DNA mutation.

The A-to-G mutation at position 8344 in the transfer RNAlysine mitochondrial DNA gene is associated mostly with the myoclonic epilepsy and ragged red fibers syndrome. We describe a five-generation family with this mutation and 19 affected members with a variant neurologic syndrome of ataxia, myopathy, hearing loss, and neuropathy. Along with axial lipomas and diabetes mellitus, hypertension is a frequent somatic feature, suggesting that mitochondrial mutations may contribute to hypertension in these patients.