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Monozygotic dichorionic twins heterokaryotypic for duplication chromosome 2q13-q23.3
1Department of Obstetrics and Gynaecology, Kwong Wah Hospital, Hong Kong, SAR, China. leungwc65@hotmail.com
Fetal Diagnosis and Therapy
|September 30, 2009
Summary
Heterokaryotypic monozygotic dichorionic twins, a rare genetic occurrence, were identified during prenatal screening. This case highlights the possibility of such twin types and their diagnostic challenges.
Area of Science:
- Reproductive genetics
- Prenatal diagnosis
- Twin studies
Background:
- Monochorionic twins share a placenta, increasing risks.
- Genetic testing is crucial for diagnosing twin zygosity and chromosomal abnormalities.
- Beta-thalassaemia major screening is a common indication for prenatal diagnosis.
Observation:
- A pair of dichorionic twins was evaluated for beta-thalassaemia major.
- Genetic analysis revealed monozygosity via QF-PCR.
- An incidental finding of heterokaryotype for duplication 2q13-q23.3 was identified using array comparative genomic hybridization.
Findings:
- The twins were confirmed as monozygotic but heterokaryotypic.
- The chromosomal abnormality involved a duplication in chromosome 2q13-q23.3.
- This genetic discrepancy within monozygotic twins was a significant finding.
Implications:
- Heterokaryotypic monozygotic dichorionic twins are a documented genetic possibility.
- Accurate genetic diagnosis is vital for understanding twin development and outcomes.
- This case underscores the complexity of twin placentation and genetics.
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