Mutations in any of the genes encoding those proteins (PDSS1, PDSS2, COQ2, COQ4, COQ5, COQ6, COQ7, COQ8A/ADCK3, COQ8B/ADCK4, COQ9) can potentially cause CoQ10 deficiency [2]. This evidence concerns the gene COQ4 and hyperinsulinemic hypoglycemia, familial, 4.