Prenatal diagnosis for two fetuses carrying partial deletion of Y chromosome
10.3760/cma.j.issn.1003-9406.2020.02.021
- VernacularTitle:两例Y染色体部分缺失胎儿的产前诊断
- Author:
Hong PANG
1
;
Ming GAO
;
Jun HUA
;
Dan TONG
;
Yanhui ZHAO
;
Xiaojing FENG
Author Information
1. 沈阳市妇婴医院 110011
- Keywords:
Y chromosome microdeletion;
Copy number variation;
SRY gene;
AZF factor
- From:
Chinese Journal of Medical Genetics
2020;37(2):182-185
- CountryChina
- Language:Chinese
-
Abstract:
Objective To perform prenatal diagosis for two fetuses carrying partial deletion of Y chromosome.Methods Routine G-and C-banding were carried out to analyze the chromosomal karyotypes of the fetuses and their fathers.Fetal DNA was also subjected to low-coverage massively parallel copy number variation sequencing (CNV-seq),fluorescence in situ hybridization (FISH),SRY gene and AZF factor testing.Results Both fetuses showed a 46,XN,del(Y)(q11.2) karyotype at 320-400 band level by the analysis of amniotic fluid chromosomes.FISH with Y chromosome centromere probe indicated that in both cases the number of Y chromosome was normal.Both fathers had an apparently normal karyotype at 320-400 band level.For fetus 1,CNV-seq test revealed a 12.88 Mb deletion at Yq11.221-q12,which encompassed the whole of AZFb+-AZFc regions and may lead to male infertility,sperm deficiency and/or severe oligospermia.In fetus 2,CNV-seq also detected a 14.84 Mb deletion at Yq11.21-q12,which encompassed the whole of the AZF region and may lead to severe spermatogenesis disorder resulting in severe oligoasthenospermia and azoospermia.In both cases,testing of SRY gene was positive.No point mutation of the SRY gene was identified.Analysis of amniotic fluid DNA confirmed partial or total absence of AZF in the two fetuses,respectively.Conclusion Combined use of various technologies can enable accurate detection of structural abnormalities of the Y chromosome and facilitate genetic counseling.CNVseq can help with rapid screening of Y chromosome microdeletions and may be used as a complementary test for chromosomal karyotyping.
