Molecular Support for Heterogonesis Resulting in Sesquizygotic Twinning
Michael T Gabbett, Johanna Laporte, Renuka Sekar, Adayapalam Nandini, Pauline McGrath, Yadav Sapkota, Peiyong Jiang, Haiqiang Zhang, Trent Burgess, Grant W Montgomery, Rossa Chiu, Nicholas M Fisk
NEW ENGLAND JOURNAL OF MEDICINE | MASSACHUSETTS MEDICAL SOC | Published : 2019
Sesquizygotic multiple pregnancy is an exceptional intermediate between monozygotic and dizygotic twinning. We report a monochorionic twin pregnancy with fetal sex discordance. Genotyping of amniotic fluid from each sac showed that the twins were maternally identical but chimerically shared 78% of their paternal genome, which makes them genetically in between monozygotic and dizygotic; they are sesquizygotic. We observed no evidence of sesquizygosis in 968 dizygotic twin pairs whom we screened by means of pangenome single-nucleotide polymorphism genotyping. Data from published repositories also show that sesquizygosis is a rare event. Detailed genotyping implicates chimerism arising at the j..View full abstract
Awarded by Research Grants Council of the Hong Kong government under the Theme-based Research Scheme
Supported by in-kind payments from Pathology Queensland, Metro North Hospital and Health Service, Brisbane, Australia, and Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Melbourne, Australia, for cytogenomics and by a grant (T12-403/15-N) from the Research Grants Council of the Hong Kong government under the Theme-based Research Scheme (to the laboratory of Dr. Chiu).