RESUMO
<p><b>OBJECTIVE</b>To identify the possible mutation at possible sites in different mitochondrial genes that leads to hearing loss in a large Chinese pedigree.</p><p><b>METHODS</b>Blood samples from a Hunan pedigree were obtained with informed consent. Genomic DNA was extracted from peripheral blood leukocytes using kit. The target fragments were amplified and detected by polymerase chain reaction (PCR) and directly sequencing respectively.</p><p><b>RESULTS</b>The result of direct sequencing revealed the A1555G mutation in 12S rRNA gene was inherited in this pedigree and no one has A7445G mutation or other mutations in its neighborhood region.</p><p><b>CONCLUSION</b>Sequence analysis confirmed that the pedigree carries the A1555G mutation. With some members ever exposure of aminoglycoside antibiotics, mutation of A1555G may play a pivotal role in the pathogenesis of hearing loss in the large pedigree.</p>