ClinVar

Description

Variant summary: COQ9 c.730C>T (p.Arg244X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 1.2e-05 in 251792 control chromosomes. c.730C>T has been reported in the literature in at-least one individual affected with Autosomal-Recessive Neonatal-Onset Primary Coenzyme Q10 Deficiency (Coenzyme Q10 Deficiency, Primary, 5, Duncan_2009). These data indicate that the variant is likely to be associated with disease. Several publications report experimental evidence and mouse models evaluating an impact on protein function (example, Duncan_2009, Lopez_2010, Garcia-Corzo_2013, Luna-Sanchez_2015, Quinzii_2010). The most pronounced variant effect resulted in ~10% of the normal coenzyme Q10 biosynthesis rate (Duncan_2009), and the generation of a homozygous mouse model with the orthologous variant R239X showed a severe CoQ10 deficiency (Garcia-Corzo_2013, Hidalgo-Gutierrez_2019). One reputed database (GeneReviews) has submitted clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic.