Two fragments of genomic and mitochodrial DNAs were amplified by polymerase chain reaction (PCR). The mtDNA A1555G mutation was identified by the Prev-DAF Testing Kit and the GJB2 235delC mutation was detected by Apa I restriction enzyme digestion method.

• 血样经DNA提取,进行GJB2 235delC突变、线粒体DNA 12SrRNA A1555G突变的检测。