Primary Coenzyme Q10 Deficiency (COQ10D)

Primary Coenzyme Q10 Deficiency (CoQ10D) is a disorder of mitochondrial cofactor biosynthesis caused by biallelic pathogenic variants in at least ten nuclear genes encoding enzymes and other proteins involved in Coenzyme Q10 (CoQ10) biosynthesis. There are several types of CoQ10D based on the affected gene: CoQ10D1 (COQ2), CoQ10D2 (PDSS1), CoQ10D3 (PDSS2), CoQ10D4 (COQ8A), CoQ10D5 (COQ9), CoQ10D6 (COQ6), CoQ10D7 (COQ4), CoQ10D8 (COQ7), and CoQ10D9 (COQ5). The manifestations of the disease range from prenatal abnormalities to neonatal encephalopathy to neurodegeneration in late adulthood. Neurological manifestations may be associated with all the disease-causing genes while the defects in the COQ8B gene cause “Nephrotic Syndrome, Type 9” (NPHS9). Oral CoQ10 therapy has been shown to reduce the disease progression and reverse certain manifestations in some patients with CoQ10D.