Triploidy caused by endoreduplication in a human zygote obtained after in-vitro fertilization.
Cytogenetic analysis of a presumably tripronuclear zygote revealed that triploidy was caused by an endoreduplicated 46,XX complement. The remaining chromosomes yielded a hyperhaploid karyotype of 28,Y, +2, +3C, +D. The origin of this chromosomal composition is obscure. Besides endoreduplication in a normal 23,X oocyte pronucleus and fertilization by a normal 23,Y spermatozoon, an additional female pronucleus might have been formed due to an irregular chromosome distribution during second meiotic division. On the other hand, penetration by a hyperhaploid spermatozoon cannot be excluded with certainty.
Rosenbusch
B
B
Department of Gynaecology and Obstetrics, University of Ulm, Germany.
Schneider
M
M
Sterzik
K
K
D000328:Adult; D004261:DNA Replication; D005260:Female; D005307:Fertilization in Vitro / Q000009:adverse effects*; D006801:Humans; D007621:Karyotyping; D008297:Male; D005810:Multigene Family; D011123:Polyploidy; D012729:Sex Chromosome Aberrations / Q000196:embryology / Q000235:genetics*; D015053:Zygote / Q000648:ultrastructure