Background
Leigh syndrome (LS) is a serious genetic disease that can be caused by mutations in dozens of different genes.
Conclusion
The m.1555A>G pathological mutation, accompanied with an unknown nuclear DNA (nDNA) factor, could be the cause of the phenotypic manifestations in this pedigree.
Methods
Clinical study of a deafness pedigree in which some members developed LS. Cellular, biochemical and molecular genetic analyses of patients' tissues and cybrid cell lines were performed.
Results
mitochondrial DNA (mtDNA) m.1555A>G/MT-RNR1 and m.9541T>C/MT-CO3 mutations were found. The first one is a well-known pathologic mutation. However, the second one does not appear to contribute to the high hearing loss penetrance and LS phenotype observed in this family.