As the number of causal SNPs increases per gene ID, its heritability on average increases. This contradicts our hypothesis. A potential reason this occurs is that as the number of causal SNPs increases per gene ID, then it is likely that the particular gene ID has more factors that determine its occurrence, which could also make it more difficult for that gene ID to be consistently heritable.

The GERP score was calculated for each gene ID in the region 500 KB from its start and stop positions. The scores were normally distributed around 0. The range of the score is from -1 to 1, with 1 meaning highly conserved. Gene IDs with small heritability and most causal SNPs had the most variation within their scores, although there are also significantly more genes in this category versus the others.

TWAS allows us to correlate the gene expression data with trait variations, meaning we can identify the specific gene IDs whose expression is significantly correlated to diseases. This is particularly effective in cancers since it is caused by a small number of mutations. We applied this technique to identify causal SNPs in Breast Invasive Carcinoma, Ovarian Serous Cystadenocarcinoma, Prostate Adenocarcinoma, and Skin Cutaneous Melanoma.