In multiple system atrophy, there is still a debate as to whether COQ2 variants are associated with disease, at least in non-Asian population, whereas at the same time evidence of coenzyme Q10 deficiency in serum and brains of MSA patients has been reported.
The COQ2p.S146N substitution has been previously reported as a pathogenic mutation in primary CoQ10 deficiency (including infantile multisystem disorder) in a recessive manner.
One patient was found to have Leigh syndrome due to a mutation in MT-ATP6, two affected siblings were discovered to be compound heterozygous for mutations in the NDUFV1 gene, which causes mitochondrial complex I deficiency, and one patient was found to have coenzyme Q10 deficiency due to compound heterozygous mutations in COQ2.
Until now, five patients from four families have been described with primary coenzyme Q10 deficiency due to mutations in COQ2 encoding para-hydroxybenzoate polyprenyl transferase.