Genes and SNPs analysed in this study.

Thirty four SNPs from 18 genes were included in this study. (−/−) = major homozygote genotype, (+/+) = minor homozygote genotype, (+/−) = heterozygote genotype, GW = genome wide association studies, * = no significance reported, ** = only reported to be significant and adult, *** = only reported to be significant in children. Chr No = chromosome number. If not otherwise indicated, all studies described here reported a significant association of the described SNP in either genotype frequency, allelic frequency or both.