Commentary: "The Etiology of Down Syndrome"

Abstract

©2019 Hultén MA. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License. It is well known that most Down Syndrome cases are of maternal origin, and that the likelihood of having a child with Trisomy 21 increases with maternal age. We have now tested the possibility that the extra chromosome in Trisomy 21 Down syndrome may be due to a segregation problem, taking place during fetal mitotic oogonial cell divisions. In this context, we have analysed the chromosome constitution in 27150 pre-meiotic oogonia from 26 fetal ovarian samples with FISH technique and found that the incidence of Trisomy 21 cell nuclei is raised at later stages of fetal oogonial development. This feature can possibly explain the maternal age effect.