title: Discontinuous gradient centrifugation (DGC) decreases the proportion of chromosomally unbalanced spermatozoa in chromosomal rearrangement carriers.
abstract: OBJECTIVE
  Can the proportion of unbalanced spermatozoa in chromosomal rearrangement carriers be decreased through the use of discontinuous gradient centrifugation (DGC)?
  
  
  CONCLUSIONS
  DGC significantly decreases the proportion of genetically unbalanced spermatozoa in chromosomal rearrangement carriers.
  
  
  BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  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.
  
  
  RESULTS
  DGC significantly decreased the proportion of unbalanced spermatozoa in all but 1 of the 21 chromosomal rearrangement carriers (P < 0.05).
  
  
  CONCLUSIONS
  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.
  
  
  CONCLUSIONS
  Used in IVF or intrauterine insemination, DGC could decrease the chance that a man carrying a chromosomal rearrangement will father an abnormal fetus.
authors: Medical Genetics and Embryology Department, AP-HP, Armand-Trousseau Hospital, 28 avenue du Dr Arnold Netter, Paris, France. alexandrerouen@gmail.com
authors: Alexandre
authors: A
authors: Rouen
authors: Richard
authors: R
authors: Balet
authors: Maud
authors: M
authors: Dorna
authors: Capucine
authors: C
authors: Hyon
authors: Xavier
authors: X
authors: Pollet-Villard
authors: Sandra
authors: S
authors: Chantot-Bastaraud
authors: Nicole
authors: N
authors: Joyé
authors: Marie-France
authors: MF
authors: Portnoï
authors: Nino Guy
authors: NG
authors: Cassuto
authors: Jean-Pierre
authors: JP
authors: Siffroi
mesh_terms: D002499:Centrifugation, Density Gradient / Q000379:methods*; D002869:Chromosome Aberrations; D025063:Chromosome Disorders / Q000517:prevention & control; D006579:Heterozygote; D006801:Humans; D008297:Male; D011446:Prospective Studies; D055101:Semen Analysis; D013094:Spermatozoa
keywords: chromosome rearrangements; density gradient centrifugation; spermatozoa; translocation