Understanding the Origin of Down Syndrome
Author Information
Author(s): Hultén Maj A, Patel Suketu D, Tankimanova Maira, Westgren Magnus, Papadogiannakis Nikos, Jonsson Anna Maria, Iwarsson Erik
Primary Institution: Warwick Medical School, University of Warwick, UK
Hypothesis
Maternal trisomy 21 ovarian mosaicism might provide the major causative factor for Down syndrome.
Conclusion
Most normal female foetuses are trisomy 21 ovarian mosaics, which may explain the maternal age effect and increased incidence of Down syndrome in subsequent conceptions.
Supporting Evidence
- All eight foetuses were found to be mosaics with an extra chromosome 21.
- The average incidence of T21 cells was 0.54% in the total cell population analyzed.
- Trisomy 21 occurred with similar frequency in meiotic and pre-meiotic cells.
Takeaway
Some babies have an extra chromosome that can cause Down syndrome, and it turns out that many mothers might have some of these extra chromosomes in their eggs even if they look normal.
Methodology
Fluorescence in situ hybridization (FISH) was used to analyze ovarian cells from eight female foetuses to determine the presence of an extra chromosome 21.
Limitations
The study is based on a small sample size of eight foetuses.
Participant Demographics
All participants were female foetuses at gestational ages of 14-22 weeks.
Statistical Information
Statistical Significance
p > 0.05
Digital Object Identifier (DOI)
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