Non-invasive prenatal testing and genetic analysis of a fetus with partial trisomy 21 / 中华医学遗传学杂志

ABSTRACT

OBJECTIVE@#To carry out prenatal diagnosis for a fetus with high risk predicted by non-invasive prenatal testing (NIPT).@*METHODS@#Next-generation sequencing (NGS) was used to analyze free fetal DNA (ffDNA) in the maternal plasma. Chromosomal karyotyping and single nucleotide polymorphism array (SNP-array) were used to ascertain copy number variation in the fetus and its parents.@*RESULTS@#SNP-array analysis and chromosomal karyotyping revealed that the fetus had a 15.018 Mb duplication at 4q34.1q35.2 and a 7.678 Mb duplication at 21q11.2q21.1, which were derived from a t(4;21)(q34.1;q21.1) translocation carried by its mother.@*CONCLUSION@#NIPT is capable of detecting submicroscopic chromosomal abnormalities of the fetus. Combined use of genetic techniques, in particular SNP-array, is crucial for the diagnosis of partial trisomy 21q in this case.