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Sex-specific chromosome instability in early human development
1St. Petersburg Centre for Medical Genetics, St. Petersburg, Russian Federation. kovaleva@robotek.ru
American Journal of Medical Genetics. Part A
|July 8, 2005
Summary
Females show a higher prevalence of chromosome abnormalities, particularly in early development. This suggests sex-specific chromosome loss and instability contribute to this female preponderance in mosaicism.
Area of Science:
- Genetics
- Developmental Biology
- Human Genetics
Background:
- The segregation of chromosome aberrations is often attributed to selection against abnormal sperm.
- However, evidence suggests early female embryos' somatic cells may also be prone to chromosome malsegregation.
Purpose of the Study:
- To investigate sex biases in chromosome abnormality carriers by comparing male to female ratios.
- To explore potential sex-specific mechanisms contributing to chromosome malsegregation.
Main Methods:
- Literature review and analysis of published data on chromosome abnormalities.
- Comparison of sex ratios in various conditions including mosaicism, uniparental disomy, and chromosome rearrangements.
Main Results:
- A female prevalence was observed in mosaicism associated with uniparental disomy (UPD), especially in early development.
- A higher incidence of 46,XX/45,X mosaics compared to 46,XY/45,X mosaics was noted.
- Females also showed a predominance in carriers of chromosome rearrangements with pericentromeric breaks.
Conclusions:
- Findings suggest sex-specific chromosome loss and centromere instability contribute to female preponderance in mosaicism.
- Females may experience gonadal mosaicism for aneuploidies and structural rearrangements more frequently than males.
- This could lead to a maternal origin bias in offspring with certain chromosomal conditions.
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