Clinical features and genetic analysis of two fetuses with ring chromosome 21 mosaicism.
10.3760/cma.j.cn511374-20220830-00589
- Author:
Yizhen JI
1
;
Yasong XU
;
Li SUN
;
Yunsheng GE
;
Meijiao CAI
;
Qichang WU
Author Information
1. Center of Prenatal Diagnosis, Women and Children's Hospital, Xiamen University School of Medicine, Xiamen, Fujian 361003, China. qichang _wu＠163.com.
- Publication Type:Journal Article
- MeSH:
Pregnancy;
Female;
Humans;
Mosaicism;
Ring Chromosomes;
Vena Cava, Superior;
Chromosome Aberrations;
Prenatal Diagnosis;
Microarray Analysis;
Fetus/diagnostic imaging*
- From:
Chinese Journal of Medical Genetics
2023;40(8):1032-1035
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE:To investigate the perinatal clinical phenotype and genetic characteristics of two fetuses with ring chromosome 21 mosaicisms.
METHODS:Two fetuses who were diagnosed at the Xiamen Maternal and Child Health Care Hospital in November 2021 were selected as the study subjects. Clinical data of the two fetuses were collected. Conventional G-banded karyotyping and chromosomal microarray analysis (CMA) were carried out for the fetuses and their parents.
RESULTS:Prenatal ultrasonography of fetus 1 has revealed absence of nasal bone, ventricular septal defect, persistent left superior vena cava, and mild tricuspid regurgitation. Chromosomal karyotyping was 46,X?,dic r(21;21)(p12q22;q22p12)[41]/45,X?,-21[9]. CMA has revealed a 30.00 Mb quadruplication at 21q11.2q22.3 and a 3.00 Mb deletion at 21q22.3. For fetus 2, ultrasonography has revealed pointed echo of the nasal bone. The fetus was found to have a karyotype of 46,X?,r(21)(p12q22)[83]/45,X?,-21[14]/46,X?,dic r(21;21)(p12q22;q22p12)[3]. CMA has revealed a 5.10 Mb quadruplication at 21q22.12q22.3 and a 2.30 Mb deletion at 21q22.3.
CONCLUSION:The perinatal phenotype of the two fetuses with ring chromosome 21 mosaicisms is related to the duplication of chromosomal segments near the breakpoints of the chromosomal deletions. The combined chromosomal karyotyping and CMA has enabled prenatal diagnosis and genetic counseling for these families.
