OBJECTIVE: To explore the genetic etiology for an infant featuring convulsive status epilepticus, developmental delay and elevated plasma lactate. METHODS: Whole exome sequencing and mitochondrial D-loop sequencing were carried out for the infant. Candidate variants were verified by Sanger sequencing. Previously reported FARS2 gene variants were searched from the PubMed, Wanfang and CNKI databases. RESULTS: The infant was found to harbor compound heterozygous variants of the FARS2 gene, namely c.925G>A (p.G309S) and c.405C>A (p.H135Q), which were inherited from its mother and father, respectively. The former has been recorded by the HGMD as a pathogenic variant, whilst the latter was predicted to be likely pathogenic based on the guidelines of the American College of Medical Genetics and Genomics. A total of 30 COXPD14 cases were retrieved from the literature, with common mutations including missense variants, in-frame deletions, splice-site variants and large deletions. CONCLUSION The common manifestations of COXPD14 have included developmental delay (96%), status epilepticus (97%) and increased lactic acid (96%). The compound heterozygous variants of the FARS2 gene probably underlay the disorder in this child.
Female ; Humans ; Infant ; Genetic Testing ; Mitochondrial Diseases ; Mitochondrial Proteins/genetics* ; Phenylalanine-tRNA Ligase ; Status Epilepticus ; Exome Sequencing

Phenylalany--tRNA synthetase is a key enzyme for protein synthesis in Trypanosoma. Its validation as an inhibition. target will enable the development of a new generation of anti-Trypanosoma drugs. However, little is known about the isolation of the Trypanosoma Phenylalanyl-tRNA synthetase. Here we report the cloning, expression, purification, and activity assay of Phenylalanyl-tRNA synthetase from Trypanosoma brucei in Escherichia coli host. We co-cloned the alpha-subunit and beta-subunit of Phenylalanyl-tRNA synthetase from Trypanosoma brucei genomic DNA into the co-expression vector pCOLADuet. We successfully expressed the Trypanosoma brucei Phenylalanyl-tRNA synthetase in E. coli host, purified the whole enzyme by Ni-Hind affinity column and verified it by Western blotting. In addition, we tested its enzymatic activity by isotope labeling. The whole work laid a solid foundation for in vitro the screening and optimization of Trypanosoma brucei phenylalanyl-tRNA synthetase inhibitors.
Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; genetics ; Phenylalanine-tRNA Ligase ; biosynthesis ; genetics ; Protozoan Proteins ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; metabolism ; Trypanosoma brucei brucei ; enzymology ; genetics