Delineation of a mosaicism fetal supernumerary marker chromosome with combined genetic techniques.
10.3760/cma.j.cn511374-20220616-00411
- VernacularTitle:联合应用多种遗传学方法鉴定1例嵌合型胎儿微小额外标记染色体
- Author:
Jingdian LU
1
;
Jian LU
;
Hong QIN
;
Xia YE
;
Juan QIU
Author Information
1. Center of Prenatal Diagnosis, Maternal and Child Health Care Hospital of Longhua District, Shenzhen, Guangdong 518109, China. 21632277@qq.com.
- Publication Type:Journal Article
- MeSH:
Humans;
Child;
Female;
Pregnancy;
Adult;
In Situ Hybridization, Fluorescence;
Mosaicism;
Genetic Techniques;
Amniotic Fluid;
Chromosomes, Human, Pair 4
- From:
Chinese Journal of Medical Genetics
2023;40(10):1296-1300
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE:To delineate the origin and content of a mosaicism small supernumerary marker chromosome (sSMC) in a fetus with combined chromosomal karyotyping, chromosomal microarray analysis (CMA) and fluorescence in situ hybridization (FISH).
METHODS:The fetus of a 31-year-old pregnant woman who had presented at the Maternal and Child Health Care Hospital of Longhua District of Shenzhen City in 2022 was selected as the study subject. Non-invasive prenatal testing suggested that the fetus has harbored a 8.75 Mb duplication in 4q12q13.1. With informed consent, amniotic fluid and peripheral blood samples were taken from the couple for chromosomal karyotyping analysis. The origin and content of a sSMC was identified by CMA, and its proportion in amniotic fluid was determined with a FISH assay.
RESULTS:The karyotypes of the pregnant woman, her husband and the fetus were respectively determined as 46,XX, 46,XY,inv(9)(p12q12), and 47,XY,inv(9)(p12q12)pat,+mar[75]/ 46,XY,inv(9)(p12q12)pat[25]. CMA test of the amniotic fluid sample was arr[hg19]4p11q13.1(48978053_63145931)×3, which revealed no mosaicism. However, FISH analysis showed that 59% of interphase cells from the cultured amniotic fluid sample had contained three signals for the centromere of chromosome 4, whilst 65% of interphase cells from the re-sampled amniotic fluid had three such signals, which confirmed the existence of trisomy 8 mosaicism.
CONCLUSION:Chromosomal structural abnormality combined with mosaicism can be delineated with combined chromosomal karyotyping and molecular techniques such as FISH and CMA, which has enabled more accurate counseling for the family.
