A synonymous polymorphism (Asp266Asp, caused by c.798C>T) is associated with sporadic PD, indicating that MTIF3 may be involved in the pathogenesis of PD (Anvret et al., 2010), and this single-nucleotide polymorphism (SNP, c.798C>T) in MTIF3 was shown to be strongly related to the PD allele by another group (Abahuni et al., 2007). Here, MTIF3 is linked to Parkinson disease.