Neonatal-Onset Primary Coenzyme Q10 Deficiency Type 5 with Multisystem Involvement: A Case Report

Primary Coenzyme Q10 (CoQ10) Deficiency Type 5 is a rare, autosomal recessive mitochondrial disorder that impairs cellular energy production. Neonatal-onset forms often present with extensive multisystem involvement and carry a poor prognosis. CoQ10, a lipid-soluble component of the mitochondrial respiratory chain, plays a crucial role in oxidative phosphorylation. Mutations affecting genes such as COQ2, COQ4, or PDSS2 disrupt CoQ10 biosynthesis, leading to various mitochondrial pathologies. We report a case of a 3-month and 3-week-old Omani male diagnosed with genetically confirmed Primary CoQ10 Deficiency Type 5. The infant presented with intractable seizures from birth, lactic acidosis, global developmental delay, hypotonia, dilated cardiomyopathy, recurrent aspiration pneumonia, and failure to thrive. Despite early initiation of high-dose CoQ10 and comprehensive multidisciplinary care, the patient continued progressive neurological and metabolic decline. This case underscores the critical importance of early genetic diagnosis and highlights the limited therapeutic efficacy of CoQ10 supplementation in severe neonatal presentations. Coordinated, multidisciplinary management and family counseling remain essential to optimize care and guide expectations.