OPA3 and axonal neuropathy: Here, we describe the members from 3 families in which a novel missense variant (c.23T>C, p.Met8Thr) and a known mutation (c.313C>G, p.Gln105Glu) in OPA3 were the most likely underlying cause of a complex phenotype consisting of OA, cataracts, gastrointestinal dysmotility, axonal neuropathy, and possibly autonomic dysfunction and hearing loss.