Genomic DNA was extracted from peripheral white blood cells. The SNPs in the CFH gene (rs3753394, rs800292, rs1061170, rs2274700, and rs1329428), C2 gene (rs9332739 and rs547154), BF gene (rs4151667, rs12614 and rs641153), LOC387715 locus (rs10490924), and HTRA1 gene (rs11200638) were amplified by polymerase chain reaction (PCR; Thermocycler 9700; Applied Biosystems, Inc. [ABI], Foster City, CA). PCR reactions were performed in 50-μL reaction volumes containing 10 mM Tris HCl (pH 8.9), 50 mM KCl, 1.5 mM MgCl2, 25 picomoles of each primer, 200 μM of each dNTP, 50 to 100 ng of patient genomic DNA, and 0.7 units of Taq thermostable DNA polymerase (Promega, Madison, WI). Cycling parameters were 3 minutes at 95°C, followed by 35 cycles of 30 seconds at 95°C, 30 seconds at the melting temperature (Tm) of the primers (52°C–62°C), and 30 seconds to 1 minute at 72°C, with a final 5-minute extension at 72°C. PCR products were purified using PCR clean-up columns (GFX; GE Healthcare, Piscataway, NJ). Sequence variations were identified by automated bidirectional sequencing (BigDye terminator chemistry, ver. 3.1; ABI). An automated DNA sequencer (Prism 3100; ABI) was used. Primers for sequence reactions were the same as those for the PCR reaction.