Primary CoQ₁₀ deficiency with a severe phenotype due to the c.901 C > T (p.R301W) mutation in the COQ8A gene

Purpose A patient with primary CoQ(10) deficiency associated with the c.901 C > T (p.R301W) (rs140246430) homozygous missense pathogenic variant in the COQ8A gene, who presented with recurrent status epilepticus, stroke-like lesions, and hypertrophic cardiomyopathy while being followed-up with early-onset autosomal recessive cerebellar ataxia will be reported in this article. Case report A 16-year-old patient who was being followed up at an external center with a diagnosis of ataxia with cerebellar atrophy had been seen 3 different times within a year for status epilepticus. The cerebral MRI showed severe cerebellar atrophy, stroke like lesions, and an inverted double- lactate peak on spectroscopy. Her echocardiography revealed marked left ventricular hypertrophy. Mitochondrial cocktail therapy containing a standard dose of CoQ(10) was started, considering mitochondrial disease. The patient died due to cardiomyopathy. Mitochondrial panel analysis revealed the presence of the c.901 C > T (p.R301W) homozygous missense mutation in the COQ8A gene. Conclusions Primary Coenzyme Q(10) deficiency should be considered in patients presenting with autosomal recessive stable-appearing progressive ataxia, emerging attacks of status epilepticus, stroke-like lesions on neuroimaging, and cardiomyopathy. Since there is a case with the same mutation with a similar fatal course in the literature, detection of c.901 C > T (p.R301W) mutation homozygously should be a warning for a severe prognosis and more aggressive treatment should be started without delay with a high dose of CoQ(10) instead of the lower doses used in the treatment of mitochondrial disease.