Table 1.

Clinical features and their prevalence according to mutation.

Clinical features	MFN2	OPA1	OPA3	PINK1
Axonal neuropathy	+++	+
Optic atrophy	+	+++	+++
Deafness	+	++
Limb girdle weakness	+	+
Progressive external ophthalmoplegia	++	++
Cataract			+++
Resting tremor, rigidity, and bradykinesia				+++
White matter periventricular involvement	+	+
3-Methylglutaconic aciduria			+++
Cognitive decline	+	+	+	+
Spasticity	++		++
Ataxia	+	+

+++: typical; ++: common; +: infrequent.