Fluorescence in-situ hybridization of sex chromosomes in spermatozoa and spare preimplantation embryos of a Klinefelter 46,XY/47,XXY male

It has been suggested recently that 47,XXY germ cells are able to progress through meiosis to produce hyperhaploid spermatozoa, We report on a 46,XY/4 7,XXY Klinefelter patient whose spermatozoa were recovered from the ejacula te and used for intracytoplasmic sperm injection (ICSI), Fluorescence in-si tu hybridization (FISH) analysis of the patient's spermatozoa and of spare preimplantation embryos with DNA probes specific for chromosomes X, Y and 1 8 revealed sex chromosome hyperploidy in 3.9% of the sperm nuclei analysed (2.23% XY18, 1.12% XX18, 0.56% YY18), while only three out of 10 spare embr yos analysed were normal for chromosomes tested. The abnormalities included two diploid mosaic embryos with the majority of the blastomeres normal for the chromosomes tested, and five embryos with mostly abnormal blastomeres and chaotic chromosome X, Y and 18 patterns, None of the embryos analysed s howed a XXY1818 or XXX1818 chromosome complement, The frequency of sex chro mosome hyperploidy in the spermatozoa of the mosaic Klinefelter patient was higher than the mean reported for karyotypically normal males, supporting the hypothesis that 47,XXY germ cells are able to complete meiosis and prod uce aneuploid spermatozoa, However, most of the spermatozoa analysed were n ormal for seu chromosomes, and ICSI of the patient's spermatozoa did not re sult in a spare embryo with a uniform 47,XXY or 47,XXX chromosome complemen t, Instead, fertilization produced a high percentage of mosaic embryos with chaotic chromosome arrangements.