The present invention provides methods, compositions, kits, systems and apparatus that are useful for determining copy number variation of one or more nucleic acids present in a sample. In some aspects, the method includes various target-specific primers that allow for the selective amplification of one or more target nucleic acids in the sample. In yet another aspect, the invention relates to determining copy number variation with respect to gene or chromosome representation of a nucleic acid in the sample. In some aspects, the method for determining copy number variation of different target nucleic acids in a sample using the disclosed methods, kits, systems and apparatuses can be used in various downstream processes including diagnosis, predictive therapeutic regimes or other therapeutic purposes.