Results
A total of 557,006 SNVs were genotyped in 2967 infants from the CHILD Cohort Study using the Illumina HumanCoreExome BeadChip. Following quality control (QC), a total of 2835 children remained for analysis, of whom 381 (13.4%) had experienced recurrent wheeze from ages 2-5 years, and 372 (13.1%) were diagnosed with asthma (including both definite and possible cases). Supplemental Data 1 and Figure S1 outlines the QC steps and the number of subjects omitted from analysis at each step. Furthermore, we determined the genetic variance (e.g. allele frequencies) explained by each of the principal components (PCs).Supplemental Figure S2 depicts changes in the eigenvalue (i.e. amount of variance captured) per addition of each PC, which demonstrates that PCs 1, 2 and 3 collectively capture the majority of genetics variance in the CHILD Cohort. Moreover, we overlaid PC plots of CHILD subjects with participants of the 1000 Genomes Project (seeSupplemental Figure S3) , which identified that 2090 CHILD subjects originated from Central Europe (approximately 74% of the CHILD Study cohort).