ORIGINAL ARTICLE Reproductive genetics Discontinuous gradient centrifugation (DGC) decreases the proportion of chromosomally unbalanced spermatozoa in chromosomal rearrangement carriers Alexandre Rouen 1, * , Richard Balet 2 , Maud Dorna 1 , Capucine Hyon 1 , Xavier Pollet-Villard 1 , Sandra Chantot-Bastaraud 1 , Nicole Joye ´ 1 , Marie-France Portnoı ¨ 1 , Nino Guy Cassuto 3 , and Jean-Pierre Siffroi 1 1 Medical Genetics and Embryology Department, AP-HP, Armand-Trousseau Hospital, 28 avenue du Dr Arnold Netter, Paris, France 2 Reproductive Medicine Unit, Bluets Hospital, Paris, France 3 ART unit, Drouot laboratory, 19 rue Drouot, Paris, France *Correspondence address. E-mail: alexandrerouen@gmail.com Submitted on January 22, 2013; resubmitted on March 13, 2013; accepted on March 27, 2013 study question: Can the proportion of unbalanced spermatozoa in chromosomal rearrangement carriers be decreased through the use of discontinuous gradient centrifugation (DGC)? summary answer: DGC significantly decreases the proportion of genetically unbalanced spermatozoa in chromosomal rearrangement carriers. what is known already: Chromosomal rearrangement carriers present with a certain proportion of unbalanced gametes, which can lead to miscarriages or malformations in the offspring. There is presently no known way to select the balanced spermatozoa and use them for IVF. study design, size, duration: The proportion of unbalanced spermatozoa after DGC was compared with that before DGC in 21 patients with a chromosomal rearrangement. At least 500 spermatozoa were analysed per observation. participants/materials, setting, methods: Twenty-one male patients with a chromosomal rearrangement were included in this prospective study. They initially consulted for infertility, recurrent miscarriages or a history of abnormal pregnancy. The samples were split into two, with one part undergoing DGC and the other being immediately fixed. Fluorescence in situ hybridization was performed to establish the chromosome segregation pattern of each spermatozoon. main results and the role of chance: DGC significantly decreased the proportion of unbalanced spermatozoa in all but 1 of the 21 chromosomal rearrangement carriers (P , 0.05). limitations, reasons for caution: Although DGC reduces the proportion of unbalanced spermatozoa in ejaculates from patients with chromosome rearrangements this elimination is only partial and some abnormal spermatozoa remain. Means to exclude these spermatozoa to ensure that only balanced ones are used in IVF remain to be discovered. The motility and morphology of the sperm before and after DGC were not measured. wider implications of the findings: Used in IVF or intrauterine insemination, DGC could decrease the chance that a man carry- ing a chromosomal rearrangement will father an abnormal fetus. study funding/competing interests: No external funding was used for this study, and none of the authors has any competing interests to declare. Key words: spermatozoa / density gradient centrifugation / chromosome rearrangements / translocation & The Author 2013. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com Human Reproduction, Vol.28, No.7 pp. 2003 –2009, 2013 Advanced Access publication on April 30, 2013 doi:10.1093/humrep/det121 Downloaded from https://academic.oup.com/humrep/article-abstract/28/7/2003/613888 by guest on 17 November 2018