Non-invasive prenatal testing and genetic analysis of a fetus with partial trisomy 21.

Author: Na MA ¹ ; Jing LIU ; Jiancheng HU ; Ying PENG ; Hui XI ; Zhengjun JIA ; Rong HU ; Hua WANG
Author Information

1. Department of Medical Genetics, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan 410008, China. wanghua213@aliyun.com.
Publication Type:Journal Article
From: Chinese Journal of Medical Genetics 2020;37(10):1079-1083
CountryChina
Language:Chinese
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.