Prenatal diagnosis of heterokaryotypic mosaic twins discordant for fetal sex

@article{Schmid2000PrenatalDO,
  title={Prenatal diagnosis of heterokaryotypic mosaic twins discordant for fetal sex},
  author={O. Schmid and Udo Trautmann and Hanan Jameel Ashour and Renate Ulmer and Rudolf A. Pfeiffer and Ernst Beinder},
  journal={Prenatal Diagnosis},
  year={2000},
  volume={20}
}
The presence of a monozygotic twin gestation with discordant sex of the twins is a very rare constellation, which is referred to as heterokaryotypic monozygotic pregnancy. This constellation can develop either due to a chromosomal aberration after twinning or is — as in the following case — due to a mitotic error before twinning and an unequal distribution of mosaicism in both embryos. So far the diagnosis of heterokaryotypic monozygotic pregnancy has always been made postnatally, with only one… 

Growth of heterokaryotic monozygotic twins discordant for Ullrich–Turner syndrome during the first years of life

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The differences of heterokaryotic MZ Turkish twins who are discordant for Ullrich–Turner syndrome are reported on, with special interest on the spontaneous and growth hormone induced growth of the twins.

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 with discordant karyotypes following preimplantation genetic screening and single embryo transfer: case report

TLDR
The discordance in the twins’ karyotypes originated from a mosaic embryo that split probably due to apoptotic process in an early stage of embryo development, one of the possible mechanisms which can explain the embryo twinning process globally.

Prenatal diagnosis of female monozygotic twins discordant for Turner syndrome: implications for prenatal genetic counselling

TLDR
It is suggested that, in cases of prenatal diagnosis of MZ female twins discordant for TS, the phenotype of each twin would be better predicted from karyotype analysis of cells from amniotic fluid than from fetal blood.

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.

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.

Heterokaryotypic Pregnancy: Monozygotic Monochorionic Twins Discordant for Trisomy 13

TLDR
This report adds to the literature the second known case of a spontaneously conceived monochorionic twin pregnancy discordant for trisomy 13 and highlights the necessity of sampling both fetuses in cases of monoch orionic twins presenting with discordant structural anomalies.

Gender-Discordant Monochorionic-Diamniotic Twins Both With 45,X/46,X, Idic(Y) Mosaicism and a Novel Deletion Within the TBC1D5 Gene

  • A. InamdarMichael DiamondW. Shertz
  • Medicine, Biology
    Pediatric and developmental pathology : the official journal of the Society for Pediatric Pathology and the Paediatric Pathology Society
  • 2020
TLDR
The case findings not only report Turner syndrome mosaicism with a novel genetic mutation but also stress the importance of clinical follow-up of twins in order to evaluate the functional abnormalities associated with isodicentric Y chromosomes including germ cell tumors.

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.

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