Chimerism in twins: Caution is needed in interpretation of karyotypes
✍ Scribed by Sylvie Bourthoumieu; Francoise Esclaire; Catherine Yardin
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 64 KB
- Volume
- 140A
- Category
- Article
- ISSN
- 1552-4825
No coin nor oath required. For personal study only.
✦ Synopsis
Interpretation of cytogenetic analysis in twins needs particular care and attention, as shown by the case of Johannsen et al. [2003], in which a child's ovaries were unnecessarily removed based on misleading cytogenetic information. Briefly, the authors reported a case of suspected monozygotic (MZ) twins with discrepant sex phenotype at birth, whereas the amniocentesis and the ultrasound examination had pointed towards male sex of both twins. In fact, at birth one twin presented as a normal boy, and the other twin as a phenotypically normal female with 46,XY blood karyotype. Gonadal dysgenesis was diagnosed, and gonadectomy was performed in the phenotypically female twin to prevent the development of a gonadoblastoma. However, the histology of the gonads revealed normal infantile ovaries, and chromosomal analysis of fibroblasts from a skin biopsy demonstrated a 46,XX karyotype. This newborn was in fact a 46,XX female with a chimeric 46,XY blood cell line due to intrauterine transfusion from her twin brother.