Two mutations (G8363A and A8296G) in the mtDNA (mitochondrial DNA) tRNA(Lys) gene have been associated with severe mitochondrial diseases in a number of reports. Their functional significance, however, remains unknown. We have already shown that homoplasmic cybrids harbouring the A8296G mutation display normal oxidative phosphorylation, although the possibility of a subtle change in mitochondri...

We report here the biochemical characterization of the deafness-associated mitochondrial tRNA(Ser(UCN)) T7511C mutation, in conjunction with homoplasmic ND1 T3308C and tRNA(Ala) T5655C mutations using cybrids constructed by transferring mitochondria from lymphoblastoid cell lines derived from an African family into human mtDNA-less (rho degrees ) cells. Three cybrids derived from an affected ma...

recurrent pregnancy loss is usually defined as the loss of two or more consecutive pregnancies before 20 weeks of gestation, which occurs in approximately 5% of reproductive-aged women. it has been suggested that women with thrombophilia have an increased risk of pregnancy loss and other adverse pregnancy outcomes. thrombophilia is an important predisposition to blood clot formation and is cons...

We have studied mitochondrial gene expression and metabolic function in a human lymphoblastoid cell-line homoplasmic for the np 7445, deafness-associated mitochondrial DNA mutation. The mutation maps to the 3' termini of the oppositely oriented genes encoding cytochrome oxidase subunit I (COI) and tRNA-ser(UCN). In comparison with control lymphoblastoid cells, we detected a marked depletion (> ...

H earing loss is a very common congenital disorder affecting one in 1000 newborns. More than 50% of deafness cases in the paediatric population have a genetic cause with autosomal dominant, autosomal recessive, X-linked, or mitochondrial patterns of inheritance. Mutations in mitochondrial DNA (mtDNA), particularly in the 12S rRNA and tRNA genes, have been found to be one of the most important c...

Increasing evidence showed that mitochondria play an important role in the development of myelodysplastic syndromes (MDS). Mitochondrial dysfunctions caused by mitochondrial DNA mutations, especially mitochondrial tRNA mutations, were found to be associated with MDS in many studies. However, the link between a candidate mitochondrial tRNA mutation and MDS was not clear. In this study, we invest...

Three tRNA genes have been isolated from a genomic library of Arabidopsis thaliana: a tRNA (GCU), a tRNA (GUA) and a tRNA (UUC) genes. These genes are located closely on the same DNA fragment. The tRNA and the tRNA genes have both 99% sequence similarity with their mitochondrial counterparts from higher plants indicating that these three tRNA genes are mitochondrial. The tRNAv gene shows a part...

Coronary heart disease (CHD) is the leading cause of death worldwide. Mitochondrial genetic determinant for the development of CHD remains poorly explored. We report there the clinical, genetic, molecular and biochemical characterization of a four-generation Chinese family with maternally inherited CHD. Thirteen of 32 adult members in this family exhibited variable severity and age-at-onset of ...

About half of the mitochondrial DNA (mtDNA) mutations causing diseases in humans occur in tRNA genes. Particularly intriguing are those pathogenic tRNA mutations than can reach homoplasmy and yet show very different penetrance among patients. These mutations are scarce and, in addition to their obvious interest for understanding human pathology, they can be excellent experimental examples to mo...

Recurrent pregnancy loss is usually defined as the loss of two or more consecutive pregnancies before 20 weeks of gestation, which occurs in approximately 5% of reproductive-aged women. It has been suggested that women with thrombophilia have an increased risk of pregnancy loss and other adverse pregnancy outcomes. Thrombophilia is an important predisposition to blood clot formation and is cons...