Which test should I apply?

#1
Hi, I have a set of of things (SNPs) which explain a percentage of variance of a trait. I got a subset of those SNPs and they explain a higher percentatge than I would expect. My question is: how I test whether the variance explained by my SNPs is significantly different than expected by chance?

Example:

15990 SNPs --> explains --> 0.107 (10 % of variance)

subset:
(expected) 67110 SNPs --------> 0.045 (4.5%)
(observed) 67110 SNPs --------> 0.067 (6.7%)

how can I test that 6.7% is significantly higher than 4.5% so that my subset of SNPs explains a higher variance?

Thanks a lot,