COQ2 and multiple system atrophy: A homozygous mutation (M78V-V393A/M78V-V393A) and compound heterozygous mutations (R337X/V393A) have been identified in the coenzyme Q2 4-hydroxybenzoate polyprenyl transferase (COQ2) gene in two familial MSA cases by using a combination method of whole-genome sequencing and linkage analysis.