The discovery sample was genotyped using the Affymetrix SNP 6.0 array (Affymetrix, Santa Clara, CA) and frequencies were compared with the Affymetrix SNP 6.0 array data available for approximately 5,000 WTCCC2 controls, originating from the National Blood Service and the 1948 British birth cohort. The replication sample genotyping was performed using KASPar chemistry.
