Associations between methylation and genetic predictors.

†Associations between methylation and SNP genotypes were tested initially under a genotypic model using a non-parametric Kruskal-Wallis Test, unless otherwise stated. Those showing association were tested further under dominant/recessive and additive models using Kruskal-Wallis and Trend tests, respectively.‡Test statistics and p-values from the most appropriate model are presented.ΦSNP GCPII/FOLHI 1561C>T and CβS 644ins were tested under a dominant model (with respect to the minor allele) only due to their low MAF (i.e. 5–15%). *A higher methylation ratio is indicative of less methylated DNA.†本研究首先采用非参数克鲁斯卡尔-沃利斯检验（Kruskal-Wallis Test），在基因型模型下检测甲基化与单核苷酸多态性（Single Nucleotide Polymorphism, SNP）基因型之间的关联，除非另有说明。对呈现关联的位点，后续分别采用克鲁斯卡尔-沃利斯检验与趋势检验（Trend test），在显性/隐性模型与加性模型下进行进一步验证。‡采用最适配模型的检验统计量与p值进行结果展示。Φ由于SNP GCPII/FOLHI 1561C>T与CβS 644ins的最小等位基因频率（Minor Allele Frequency, MAF）较低（即5%~15%），故仅在以次要等位基因为参照的显性模型下对其进行检测。*甲基化比率越高，代表DNA的甲基化程度越低。