Mutational Analysis of Mitochondrial tRNA Genes in Patients with Asthma

Background: Mitochondria are autonomous cellular organelles that oversee a variety of functions such as metabol-ism, energy production, calcium buffering, and cell fate determination. Most recently, mitochondrial dysfunction caused by mitochondrial mutations played important roles in the pathogenesis of asthma. However, the frequency of mitochondrial tRNA mutations in asthma is largely unknown. Methods: Overall, 200 patients with asthma and 100 healthy control subjects were recruited between Jan 2015 and Dec 2015 at the Guangming New District People's Hospital, Shenzhen, Guangdong Province, China. We first per-formed PCR amplification of the mitochondrial tRNA genes and subsequently sequenced the PCR products, and we used the pathogenicity scoring system to evaluate the potential role of these mutations. Results: Two patients carrying the tRNAThr G15927A mutation, three patients carrying the tRNAAla T5655C muta-tion and one patient carrying the tRNAGlu A14693G mutation, these mutations were absent in healthy controls. More-over, these mutations located at positions highly conserved between different species, and may cause a failure in mito-chondrial tRNA metabolism, consequently result in mitochondrial dysfunction that responsible for asthma. In addi-tion, the pathogenicity scoring system showed that these mutations should be regarded as “pathogenic”. Conclusion: Mitochondrial tRNA mutations caused the mitochondrial dysfunction may be involved in the pathoge-nesis of asthma. Thus, this study provided novel insight into the molecular mechanism underlying mitochondrial tRNA mutations in asthma. Moreover, screening for the mitochondrial tRNA mutations was advised for the diagnosis of patients with asthma.