map genomic regions to genes

Question

[sabin]

Hi everyone, I have a question about mapping genomic regions to genes. Beside taking the genes matching to the regions, which is the search radius to consider to include also near genes? I've read somewhere that 150k bp is a default radius. So I was wondering if setting a search radius of 200k it would be too much.

Ps. I want to map differentially methylated regions to genes.

Thanks for the help!