Be. Rosenbusch et al., TETRAPLOIDY AND PARTIAL ENDOREDUPLICATION IN A TRIPRONUCLEAR ZYGOTE OBTAINED AFTER INTRACYTOPLASMIC SPERM INJECTION, Fertility and sterility, 69(2), 1998, pp. 344-346
Objective: To describe a peculiar combination of cytogenetic abnormali
ties in a tripronuclear zygote obtained after intracytoplasmic sperm i
njection (ICSI).Design: Case report. Setting: A university hospital. P
atient(s): A couple with a 4-year history of primary infertility. Intr
acytoplasmic sperm injection was performed because of male factor infe
rtility (oligoteratozoospermia). Intervention(s): Ultrasound-guided tr
ansvaginal follicular aspiration. Main Outcome Measure(s): Chromosomal
karyotype of a tripronuclear one-cell zygote. Result(s): Unexpectedly
, a tetraploid [92,XXYY,end3,-18,-18,end18] chromosome complement was
found, indicating injection of a diploid spermatozoon carrying two Y c
hromosomes. The parental origin of the other abnormalities could not b
e determined. The missing chromosomes may be attributed either to a hy
podiploid [44,YY,-18,-18] sperm cell or to a hypohaploid [22,X,-18] oo
cyte. The exact tetraploid count was restored by endoreduplication of
two chromosomes. This event could have occurred in one and the same or
in two different pronuclei. Conclusion(s): Cytogenetic analysis of mu
ltipronuclear zygotes appears useful for assessing the incidence of ch
romosomal abnormalities at the earliest stage of conception. In additi
on to other methods, it also may contribute to evaluation of the trans
mission of aberrations by spermatozoa from infertile men. (C) 1998 by
American Society for Reproductive Medicine.