Haplotype Analysis
To determine relatedness between families identified with BRCA1 promoter methylation, we genotyped 12 BRCA1 intragenic SNPs by Sanger sequencing to determine ancestral haplotypes (Supplemental Material and Methods).20 In addition, genotyping using Affymetrix Genome-Wide SNP6.0 arrays was undertaken according to the manufacturer’s protocol. Genotypes and copy-number data were generated within the Affymetrix Genotyping Console (v.4.1.3.840) via the Birdseed V2 algorithm and SNP 6.0 CN/LOH algorithm, respectively.