Investigation of <i>TMEM70</i> Gene Mutations Involved in Mitochondrial ATP Synthesis Pathway in Two Khuzestan Families

Background: Mitochondrial complex V deficiency refers to a shortage (deficiency) of a protein complex called complex V or a loss of its function. The TMEM70 gene provides the blueprint for mitochondrial ATP synthase, a protein essential for cellular energy production through oxidative phosphorylation. The diagnostic method based on whole-exome sequencing (WES) provides more appropriate genetic counseling by saving time and money. Methods: This study investigated three patients presenting with similar clinical symptoms using WES. After DNA extraction, WES was performed, and a novel mutation (c.311T > G: p.V104G) in the TMEM70 gene was identified. Sanger sequencing was used to confirm the variant in the parents. Results: The novel TMEM70 mutation (c.311T > G: p.V104G) was identified as a potential cause of the disease in these patients. Conclusions: This study highlights the utility of WES in the rapid and cost-effective identification of pathogenic variants associated with mitochondrial disorders. The identification of a novel TMEM70 mutation underscores the importance of this gene in mitochondrial function and further emphasizes the need for comprehensive genetic screening in individuals presenting with clinical symptoms consistent with mitochondrial ATP synthase deficiency. Further research is needed to elucidate the specific functional consequences of this mutation and to investigate the prevalence of TMEM70 mutations in various populations.