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Down syndrome with trisomy in one triplet
American Journal of Diseases of Children (1960)
|May 1, 1977
Summary
This case report details the first instance of Down syndrome (21 trisomy) in a triplet, with genetic testing suggesting dizygotic (fraternal) origins for the surviving twins.
Area of Science:
- Genetics
- Perinatology
- Immunology
Background:
- Triplets present complex genetic and developmental scenarios.
- Down syndrome (21 trisomy) is a chromosomal disorder.
- Distinguishing monozygotic from dizygotic twins can be challenging.
Observation:
- A triplet pregnancy resulted in one infant diagnosed with Down syndrome (21 trisomy).
- Initial blood group testing suggested identical twins, but further analysis revealed discrepancies.
- One triplet passed away in infancy with non-distinctive facial features.
Findings:
- Advanced genetic analyses, including chromosome fluorescent banding, mixed lymphocyte culture, and HLA typing, indicated dizygotic (fraternal) origins for the surviving twins.
- Skin transplantation compatibility further supported dizygotic twinning.
Implications:
- This case highlights the importance of comprehensive genetic testing in complex multiple gestations.
- Understanding zygosity is crucial for accurate diagnosis and genetic counseling in cases of Down syndrome within multiple births.
- The findings contribute to the understanding of zygosity determination and its clinical relevance.