‘Identical’ twins with discordant karyotypes

@article{Nieuwint1999IdenticalTW,
  title={‘Identical’ twins with discordant karyotypes},
  author={Aggie W. M. Nieuwint and R. M. van Zalen‐Sprock and Pieter Hummel and Gerard Pals and John M. G. van Vugt and Hans J. van der Harten and Y M Heins and Kamlesh Madan},
  journal={Prenatal Diagnosis},
  year={1999},
  volume={19}
}
A chromosomal abnormality in one of the fetuses of a monozygotic twin pregnancy is a rare phenomenon. [] Key Result Chromosomal analysis showed that one twin pregnancy was discordant for trisomy 21 and the other for 45,X. Ultrasonographic examination suggested a monochorionic twin pregnancy in each case and DNA studies confirmed that both sets of twins were monozygotic. Both pregnancies were terminated. Biopsies taken from different sites of the placentas showed chromosomal mosaicism in both cases.

Discordant Prenatal Phenotype and Karyotype of Monozygotic Twins Characterized by the Unequal Distribution of Two Cell Lines Investigated by Different Methods: A Review

TLDR
It is suggested that in cases of a phenotypic discordance detected at ultrasound in the first trimester, it is advisable to perform a karyotype analysis on amniocytes because it better reflects fetal constitution rather than chorionic villi or lymphocytes in case of heterokaryotipic monosomy X monochorionic twins.

Monozygotic twins discordant for trisomy 18

  • A. ReussH. Gerlach B. Eiben
  • Medicine
    Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology
  • 2011
TLDR
This report reports on the pre‐ and postnatal cytogenetic, molecular genetic and clinical findings in monochorionic‐diamniotic twins discordant for trisomy 18, which led to elective Cesarean section in one of the twins and the aneuploid twin died shortly after delivery.

Monozygotic twins discordant for trisomy 13

TLDR
The various mechanisms by which monozygotic twins may have discordant karyotypes are discussed, and the surviving twin will be monitored for potential complications of uniparental disomy of chromosome 13 and trisomy 13 mosaicism.

Monozygotic Twins Discordant for Monosomy 21 Detected by First-Trimester Nuchal Translucency Screening

TLDR
Study of such cases may reveal the extent to which an early diagnosis of monochorionic twins discordant for fetal abnormalities can lead to therapeutic interventions to support survival of the viable twin.

Monozygotic twins concordant for blood karyotype, but phenotypically discordant: A case of “mosaic chimerism”

TLDR
It is suggested that blood is particularly unsuitable for cytogenetic investigations of twins, as shown by twin‐to‐twin transfusion syndrome observed during fetal life of the authors' twins.

Monozygotic twins discordant for homologous Robertsonian translocation trisomy 21 of 46, XX, + 21, der (21;21) (q10; q10) in a twin-to-twin transfusion syndrome, case report

TLDR
The early detection of discordant karyotype and twin-to-twin transfusion syndrome is beneficial to the early intervention and should be considered in monozygotic twins with a discordant anomaly.

Chimerism in twins: Caution is needed in interpretation of karyotypes

TLDR
A case of suspected monozygotic twins with discrepant sex phenotype at birth, whereas the amniocentesis and the ultrasound examination had pointed towards male sex of both twins, which was in fact a 46,XX female with a chimeric 46,XY blood cell line due to intrauterine transfusion from her twin brother.

DIFFICULT DIAGNOSIS AND MANAGEMENT OF AN HETEROKARYOTYPIC MONOCHORIONIC TWIN PREGNANCY WITH DISCORDANT FETAL SEX AND 45,X/47,XYY KAROTYPES

TLDR
The difficult diagnosis and management of a monochorionic twin pregnancy with discordant fetal sex is shown.

Prenatal Diagnosis and Management of Monozygotic Twins Discordant for Turner Syndrome

TLDR
This work presents 2 cases of MZ twins discordant for Turner syndrome that were diagnosed prenatally by ultrasound and cytogenetic studies and underwent selective feticide, which resulted in favorable outcomes for the remaining twin.
...

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