Massively Parallel Sequencing (MPS) of Cell-Free Fetal DNA (cffDNA) for Trisomies 21, 18, and 13 in Twin Pregnancies
In: Twin research and human genetics: the official journal of the International Society for Twin Studies (ISTS) and the Human Genetics Society of Australasia, Band 20, Heft 3, S. 242-249
ISSN: 1839-2628
Massively parallel sequencing (MPS) technology has become increasingly available
and has been widely used to screen for trisomies 21, 18, and 13 in singleton
pregnancies. This study assessed the performance of MPS testing of cell-free
fetal DNA (cffDNA) from maternal plasma for trisomies 21, 18, and 13 in twin
pregnancies. Ninety-two women with twin pregnancies were recruited. The results
were identified through karyotypes of amniocentesis or clinical examination and
follow-up of the neonates. Fluorescent in-situ hybridization was used to examine
the placentas postnatally in cases of false-positive results. The fetuses with
autosomal trisomy 21 (n = 2) and trisomy 15 (n
= 1) were successfully detected via MPS testing of cffDNA. There was one
false-positive for trisomy 13 (n = 1), and fluorescence in-situ
hybridization (FISH) identified confined placental mosaicism in this case. For
twin pregnancies undergoing second-trimester screening for trisomy, MPS testing
of cffDNA is feasible and can enhance the diagnostic spectrum of non-invasive
prenatal testing, which could effectively reduce invasive prenatal diagnostic
methods. In addition to screening for trisomy 21, 18, and 13 by cffDNA, MPS can
detect fetal additional autosomal trisomy. False-positive results cannot
completely exclude confined placental mosaicism.