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We question whether, in men with an abnormal rate of sperm DNA fragmentation, the magnetic-activated cell sorting (MACS) could select spermatozoa with lower rates of DNA fragmentation as well as spermatozoa with unbalanced chromosome content. Cryopreserved spermatozoa from six males were separated into nonapoptotic and apoptotic populations. We determined the percentages of spermatozoa with (i) externalization of phosphatidylserine (EPS) by annexin V-Fluorescein isothiocyanate (FITC) labeling, (ii) DNA fragmentation by TdT-mediated-dUTP nick-end labeling (TUNEL), and (iii) numerical abnormalities for chromosomes X, Y, 13, 18, and 21 by fluorescence in situ hybridization (FISH), on the whole ejaculate and selected spermatozoa in the same patient. Compared to the nonapoptotic fraction, the apoptotic fraction statistically showed a higher number of spermatozoa with EPS, with DNA fragmentation, and with numerical chromosomal abnormalities. Compared to the whole ejaculate, we found a significant decrease in the percentage of spermatozoa with EPS and decrease tendencies of the DNA fragmentation rate and the sum of disomy levels in the nonapoptotic fraction. Conversely, we observed statistically significant higher rates of these three parameters in the apoptotic fraction. MACS may help to select spermatozoa with lower rates of DNA fragmentation and unbalanced chromosome content in men with abnormal rates of sperm DNA fragmentation. [ABSTRACT FROM AUTHOR]

Small supernumerary marker chromosomes (sSMCs) are defined as structurally abnormal chromosomes that are difficult to identify by conventional cytogenetic techniques. sSMCs are 3.75 times more common in infertile men than in the general population. This study aimed at characterizing a supernumerary marker chromosome in a nonconsanguineous infertile couple and analyzing its meiotic segregation in sperm by multicolor FISH. The male partner's karyotype was mos 47,XY,+idic(15)(pter→q11.1::q11.1→pter)[6]/46,XY[24].ish idic(15)(NOR+,D15Z3+,SNRPN–,D15Z3+,NOR+). In triple FISH using CEP 15, BAC 15, and BAC 21 probes, 4,227 spermatozoa of the patient were analyzed, and the sSMC was detected in only 0.66% of spermatozoa. In triple FISH employing CEP X, CEP Y, and BAC 18 probes, 2,008 spermatozoa of the patient were analyzed. The frequency of disomic and diploid sperm was not significantly different from control donors. To our knowledge, segregation of an sSMC 15 has been reported in only 9 males with non-mosaic karyotypes. These studies described rates of spermatozoa with sSMC 15 ranging from 6.23% to more than 50%. In this work, we report the first meiotic segregation analysis of a chromosome 15-derived sSMC in spermatozoa of a patient with a mosaic karyotype. The low rate of spermatozoa with sSMC detected is concordant with the low proportion of abnormal cells in our patient's lymphocytes. Moreover, the risk of interference of this sSMC with other chromosomes seems minimal. Genetic counseling was recommended given that the risk of chromosomal imbalance in the fetus linked to paternal sSMC was very low. Finally, a healthy boy was born after a natural pregnancy. [ABSTRACT FROM AUTHOR]

A letter is presented that discusses a probably LMBRD1-CHD6 fusion resulting from a novel translocation in acute myeloid leukemia.