Very few people here are doctors in medicine. I certainly am not. I know how to munch data files, but my knowledge of chromosomes extend as far as "they exist" and "i have some of those".

Could you provide a short example file(s) and a (hand crafted) file of the expected output? Also, a non-scientist explanation for us software developers in the form of "column A of this file example1 needs to get concatenated to column B of file example2 if column C in example2 matches part of column X in example2". E.g. a bit more abstracted/technical without requiring 10 years of university work.