A comparative genomic hybridization method to assess the presence and number of copy number variations throughout a test DNA, wherein the sex of the donor of said test DNA is unknown, said method comprising the steps of: a) labeling with a first marker, said test-DNA, thus obtaining a labeled test-DNA; b') labeling with a second marker, different from the first, a male reference-DNA, thus obtaining a labeled male reference-DNA, or b") labeling with a second marker, different from the first, a female reference-DNA, thus obtaining a labeled female reference-DNA, c) hybridizing the DNAs obtained in steps a) and b') or a) and b") to a test hybridization array, thus obtaining a combined pattern of signal intensities from both markers; d) from the combined pattern of step c), determine the single signal intensities produced by the said first and second marker; e) perform a first evaluation of CNV in said test-DNA, by comparing against each other the two signal intensities obtained in step d); f) labeling with said first marker, a reference-DNA sexually opposite to the one used in steps b') or b") respectively, thus obtaining a reference-DNA labeled with said first marker; g) labeling with said second marker different from the first, said reference-DNA being sexually opposite to the one used in steps b') or b"), thus obtaining a reference-DNA labeled with said second marker; h) hybridizing both DNAs obtained in steps f) and g) to a reference hybridization array, thus obtaining a combined pattern of signal intensities acquired from both markers; i) from the combined pattern of step h), determine the single signal intensities produced by the said first and second marker; j) perform a second evaluation of CNV in said test-DNA, by comparing against each other: - the signal intensity of said test-DNA labeled with said first marker, as determined in step d), - with the signal intensity of said reference-DNA labeled with said second marker as determined in step i); k) perform a software-assisted combination of the CNV values obtained in steps e) and j) to provide a complete and final CNV profile of the whole test DNA subjected to analysis; wherein, in alternative to performing said steps f) through i), the signal intensities referred in step i), previously obtained by performing said steps f) through i), can be obtained from a data storage support where they were previously recorded, wherein said male reference-DNA has been obtained from one or more male donors, and/or said female reference-DNA has been obtained from one or more female donors and wherein the method includes only a single step of test DNA hybridization, consisting of step c). a) labeling with a first marker, said test-DNA, thus obtaining a labeled test-DNA; b') labeling with a second marker, different from the first, a male reference-DNA, thus obtaining a labeled male reference-DNA, or b") labeling with a second marker, different from the first, a female reference-DNA, thus obtaining a labeled female reference-DNA, c) hybridizing the DNAs obtained in steps a) and b') or a) and b") to a test hybridization array, thus obtaining a combined pattern of signal intensities from both markers; d) from the combined pattern of step c), determine the single signal intensities produced by the said first and second marker; e) perform a first evaluation of CNV in said test-DNA, by comparing against each other the two signal intensities obtained in step d); f) labeling with said first marker, a reference-DNA sexually opposite to the one used in steps b') or b") respectively, thus obtaining a reference-DNA labeled with said first marker; g) labeling with said second marker different from the first, said reference-DNA being sexually opposite to the one used in steps b') or b"), thus obtaining a reference-DNA labeled with said second marker; h) hybridizing both DNAs obtained in steps f) and g) to a reference hybridization array, thus obtaining a combined pattern of signal intensities acquired from both markers; i) from the combined pattern of step h), determine the single signal intensities produced by the said first and second marker; j) perform a second evaluation of CNV in said test-DNA, by comparing against each other: - the signal intensity of said test-DNA labeled with said first marker, as determined in step d), - with the signal intensity of said reference-DNA labeled with said second marker as determined in step i); - the signal intensity of said test-DNA labeled with said first marker, as determined in step d), - with the signal intensity of said reference-DNA labeled with said second marker as determined in step i); k) perform a software-assisted combination of the CNV values obtained in steps e) and j) to provide a complete and final CNV profile of the whole test DNA subjected to analysis;