Vein blood samples 4-6ml were collected and Genomic DNA were extracted. Exon 9 of CFH gene was PCR amplified .

• 抽取外周抗凝血4-6ml,用酚-氯仿抽提法提取全基因组DNA,聚合酶链反应(Polymerase chain reaction ,PCR)扩增外显子9片断并进行直接测序。