I am heterzygous for this mutation. (Listed in my results as i5008699) Interesting thanks imdcout.
6 of the 31 ME patients I have full 23andMe data and controls for are heterozygous for it. But so are 4 controls. I'm not quite sure what to make of that, since I can't find any prevalence data for it. I'll check the databases I've downloaded in a bit.
That particular SNP is labeled in
OMIM as being associated with Hereditary Motor and Sensory Neuropathy, Type VIA. Type 6 is associated with early onset muscle weakness and optic atrophy. It's autosomal dominant on MFN2, so being heterozygous is sufficient to develop the disease. But that also means that typically one parent will also have the disease.
There's not much data about type 6A (abbreviated HMSN6A), really just at
http://www.omim.org/clinicalSynopsis/601152 . But it looks like it might be heavier on the neurological involvement than some of the other types.
I'll try to look into our data for the relevant genes a bit later.