Episodic ataxia and hemiplegia caused by the 8993T->C mitochondrial DNA mutation

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J Med Genet. 2007 Dec;44(12):797-9.

Episodic ataxia and hemiplegia caused by the 8993T->C mitochondrial

DNA mutation.

Craig K, Elliott HR, Keers SM, Lambert C, Pyle A, Graves TD,

Woodward C, Sweeney MG, MB, Hanna MG, Chinnery PF.

M41014, The Medical School, Framlington Place, Newcastle upon Tyne,

NE2 4HH, UK

The m.8993T-->C MTATP6 mutation of mitochondrial DNA (mtDNA) usually

causes mitochondrial disease in childhood, but was recently

described in a family with adult onset ataxia and polyneuropathy.

Cytochrome c oxidase muscle histochemistry, which is the standard

clinical investigation for mitochondrial disease in adults, is

usually normal in patients with MTATP6 mutations. This raises the

possibility that these cases have been missed in the past.

We therefore studied 308 patients with unexplained ataxia and 96

patients with suspected Charcot-Marie-Tooth disease to determine

whether the m.8993T-->C MTATP6 mutation is common in unexplained

inherited ataxia and/or polyneuropathy. We identified a three-

generation family with the m.8993T-->C mutation of mtDNA. One

subject had episodic ataxia (EA) and transient hemipareses,

broadening the phenotype.

However, no further cases were identified in an additional cohort of

191 patients with suspected EA. In conclusion, m.8993T-->C MTATP6

should be considered in patients with unexplained ataxia, CMT or EA,

but cases are uncommon.